GEAR AND GADGETS : Frequent Flier Puts Newest Carry-ons to the Test : How four lines of roll-aboard luggage meet the challenge of getting those bags on board.

As a frequent flier, I long ago calculated the amount of time and aggravation I saved by limiting myself to carry-on luggage whenever possible. No long waits at baggage claim carousels for me or--worse--no chances that while I headed for Cancun my suitcase was bound for Cleveland.

The big drawback was that since I schlepped as much as I could and as much as the gate agent would allow me to drag onto the plane, I often ended up with sore neck, arm and back muscles. After lugging my stuff down long airport corridors, I then inevitably had to wait, all loaded up, while the guy blocking my seat ever-so-slowly folded his sports jacket and placed it in the overhead compartment.

The advent of luggage wheels helped tremendously--especially with those airport corridors--but I still had to dismantle everything when I got on the plane, since my carry-on seldom wheeled easily down the narrow aisles. And then I was left having to fold down, tie up and store the darn wheels--which the gate agent sometimes counted as a piece of carry-on baggage, thus limiting my potential haul.

Happily, roll-aboard luggage has come to the rescue. With their built-in wheels and cushioned retractable handles, the bags roll smoothly down most airplane aisles. Their svelte measurements (20 to 22 inches long, about 13 inches wide and 8 inches deep) make for an easy fit under the seat and in most overhead bins.

Originally, the bags were manufactured by only one company, Travelpro, which marketed them by mail order. They sold extremely well, and now the biggies in the luggage biz--American Tourister, Lark, Samsonite--all produce wheel-aboard lines of their own.

I recently tested the offerings of all four major players on the ground and in the air. All the bags were solidly constructed (as you’d expect from the pros) and handled well on the move--easily taking on steep curbs, bouncing down stairs and, for the most part, rounding corners. The big differences were in styling and cosmetic touches, so choice is likely to be as much a matter of taste as quality: The best way to pick a bag is to inspect several yourself. All the models mentioned are available at major department stores or luggage specialty outlets, which may discount them from the list price noted.

Made of a tough nylon fabric that took a lot of banging and shoving during my trip, the Travelpro Rollaboard came through with flying colors. While the top and bottom are soft, the sides are reinforced so the bag will not collapse. Expandable outside zippered compartments were great for getting in extra clothes and some paperback books at the last minute (though this kept the bag from fitting under the airplane seat or in the overhead bin, and had to be emptied before storing the bag). I liked that the interior was just one big compartment--my choice for stuffing in the most gear. I would have felt more secure with a heavier-weight zipper, although the Rollaboard’s never snagged, no matter how much I overstuffed the bag.

My favorite Rollaboard innovations are the recently introduced optional duffel bag and portfolio tote, which have special clasps that hook onto a knob on the bag. (Bags without the clasps can be hung from the Rollaboard’s detachable hook or pull-up handle.) Both the duffel and the tote are made of the same tough material as the Rollaboard and have zippered exterior compartments and detachable shoulder straps.

Travelpro Rollaboard, in black or navy, comes in two sizes: 20-inch length, $150; 22-inch length, $170. Duffel and tote, $60 each.

The American Tourister Commuter Carry-on is basically a fancy clone of the Travelpro Rollaboard. A press release says American Tourister’s models are more solidly constructed and, in tests, took more of a beating before breaking. The Commuter is indeed a heavier-built bag, with extra supports and padding not found in the Travelpro (but this also makes it a slightly heavier bag). Tailoring and colors (such as teal or charcoal) are more upscale. The nylon net zippered compartment inside the lid makes finding stored items easier than with the Rollaboard’s solid black nylon compartment, and I liked the detachable, zippered plastic wet pack for separating damp and soiled items from other clothing. Like the Travelpro Rollaboard, the Commuter has a detachable hook for hanging other bags, as well as several outside pockets.

The Commuter Carry-on comes in two versions, each part of a line of color-and-fabric-coordinated luggage--a plus if you’ve already got some of these.

American Tourister Commuter Carry-on, about 23 inches long. Ambiance Collection, $150; Genesis Collection, $180.

Long synonymous with classy luggage--and prices to match--Lark offers two styles of E-Z Travel wheel-aboard bags, a soft model and one called Permaflex, which is almost a hard bag. Both are gorgeous, with sleek styling, fine stitching and linings, and Lark’s signature red, gray and green-striped sash. Both bags match the company’s extensive line of luggage and accessories.

The Permaflex E-Z Wheeler was the only bag tested that had a heavy-duty zipper (a plus), which opens to reveal two zippered interior compartments. This may be favored by those who like to organize their clothes for easy access. The Permaflex bag also has a detachable wet sack for soiled or damp items. A strap pulls out from the wide plastic retractable handle for securing “piggyback” bags, and the wheels are extra large for sturdiness.

I wasn’t crazy about the Permaflex bag. Without external pockets, it had much less storage space than other wheel-aboards; in addition, the retractable handle is so far recessed into the bottom of the bag that precious packing space is lost.

There’s a lot more space in Lark’s Soft E-Z Wheeler carry-on. The case has two outside pockets (the one on the lid opens from the inside as well), and a removable waterproof pouch for damp or soiled items.

The bag is deeper than other roll-aboard models, which made it slightly harder to squeeze into some overhead bins and under the seats. Another disadvantage is that, unlike most other roll-aboards, the retractable handle pulls out from the narrowest side of the bag. While this makes for easy wheeling down airplane aisles too narrow for other roll-aboards, the design is not conducive for hanging additional bags. Nor is there a hook for accessory totes.

In October, Lark is due out with a soft piggyback bag that has two outside pockets--a much more attractive option than its two predecessors.

Lark Permaflex E-Z Wheeler, 21 inches long, $315; Soft E-Z Wheeler, 21 1/4 inches, $260.

Samsonite’s Silhouette 4 hard and soft roll-aboard carry-ons are for the most part down-home versions of Lark’s Permaflex E-Z Wheeler and Soft E-Z Wheeler, respectively--and therefore share the same pluses and minuses. That’s no surprise, since Samsonite owns Lark, which is its high-end alter ego. There are differences: The Samsonite hard piggyback latches shut (instead of zipping shut like the Permaflex E-Z Wheeler); it has one zippered interior compartment instead of two, and the outside pockets on the Lark and Samsonite models differ in design. Other than that, the differences are mainly in material and cosmetic flourishes. The Silhouette 4 bags are part of an extensive line of matching luggage.

Samsonite Silhouette 4 hard Piggyback Carry-on, 21 3/4 inches long, $190; soft carry-on, 22 inches, $150.

Which bag gets my vote for top wheel-aboard? As mentioned, there’s a lot of personal taste involved. I’m partial to the original Travelpro Rollaboard and its upscale clone, the American Tourister Commuter Carry-on, because both have lots of interior packing space and exterior pockets, and accommodate piggyback bags well. The Travelpro has a handier latching system for additional bags; the American Tourister has a wider range of matching accessories and is built a bit sturdier and with finer attention to detail. Either should provide heavenly wheeling for many years to come.