If you've spent any time in Mexico or the American Southwest, you know that some very, very good things come wrapped in flour tortillas. From barbacoa to fajitas, and from burritos to chimichangas, these humble shells deliver all manner of tasty delights.

Leave it to the American fast-food and quick-service industry to take that idea and suck all the fun out of it.

Sometime during the Atkins Diet craze, some bright boy or girl figured out that a slender tortilla has a lot fewer carbs than a big honkin' bun. What followed was a sad sight: Every combination of meat, cheese and vegetables that could be jammed into a tortilla was, whether or not it made a lick of sense.

And the tortillas themselves? If you've ever had a fresh tortilla that hit the press and then the grill within the last day, the vinyl-like texture of your average drive-through tortilla might just make you start sobbing before you get your change. All in all, the Americanized wrap bears very little resemblance to anything traditionally put into a tortilla, and certainly doesn't even vaguely approximate the kind of complex flavors normally expected.

However, there are some promising signs that the big players are beginning to realize the flavor potential a wrap possesses, and you might even be surprised by who's jumped on the flavor train in the biggest way.

All the wraps are graded on an A-F scale, with the final grade comprising the freshness and flavor of both the fillings and the tortilla.

Nutritional information, if available, is provided for each wrap. It should be noted that some wraps are "snack" wraps, whereas some are intended to be full meals. I've noted which is which.

KFC Toasted Snack Wrap (with Crispy Strip): 350 calories, 19 grams fat, 40 mg cholesterol, 880 mg sodium, 29 grams carbs.

The Colonel's joint has not fared well in previous tests, but this sandwich gets it almost perfect. The grilled tortilla's flavor is excellent, and the cheese melts nicely to hold the whole thing together. My only fault was that the lone strip was somewhat lost in the size of the tortilla. The bites contained too much bread and too little chicken. Still, it earned a solid B+.

Sonic Chicken Strip Wrap: 470 calories, 20 grams fat, 40 mg cholesterol, 1,310 mg sodium, 54 grams carbs.

Sonic has done pretty well in previous chicken tests. The chain's luck runs out here, though. The tortilla was tied for the worst of the bunch -- tough and leathery without a trace of freshness, and the overall flavor was just about as plain as it could be. The "lite" ranch dressing was fairly tasty, but couldn't bring the whole above a C-.

Arby's Roast Turkey Ranch & Bacon Wrap: 682 calories, 36 grams fat, 102 mg cholesterol, 2,103 mg sodium, 42 grams carbs.

This wrap sounds like it should be great, but it just doesn't follow through. Arby's tied Sonic for worst tortilla. The wrap looks great, bursting with fresh leaf lettuce, red onion, tomato, cheddar and the meats. However, it's as if some flavor-blocking elixir has been sprinkled on the whole thing. Perhaps there's just too much going on for any of the single flavor notes to stand out. Based almost solely on the tasty appearance, this one earns a C.

Chick-Fil-A Spicy Chicken Cool Wrap: 410 calories, 21 grams fat, 60 mg cholesterol, 1,340 mg sodium, 44 grams carbs.

This article marks Chick-Fil-A's debut in our comparison ranks, and I'm glad to have it here. This is a really good wrap, with tasty chicken, two cheeses, romaine lettuce, red cabbage and tomato. The spicy dressing, served in a packet on the side, has some real kick. For real drive-through convenience, the dressing really should be served on the wrap. That's a small bobble, though, still allowing the final score of A-.

McDonald's Chipotle BBQ Snack Wrap (crispy): 330 calories, 15 grams fat, 25 mg cholesterol, 800 mg sodium, 35 grams carbs.

This snack wrap is actually available in three flavors. I chose the spicier version. This was our winner by a nose over the Chick-Fil-A offering, and a huge surprise given McD's past performance. The tortilla was fresh and tender, almost straight-off-the-grill in texture. The chicken was plentiful, the cheese perfectly melted and the chipotle sauce had a real kick that surprised my tastebuds. The House of Ronald earns a solid A, winning this round.

Does this signal a weather change in the McDonald's menu? Will meat grinders suddenly appear in every restaurant, making Big Macs by the hundreds daily? I somehow doubt it. But the fact that the biggest name in the business got it so very right this time gives one hope for future new products.