The Alox knives are thinner, making them easier to carry in a pocket. They're also more durable, but again, I've never broken a SAK handle. If I do, I'm probably doing something that I shouldn't be doing with it. The texture of the Alox also gives you a solid grip, while the normal (cellidor) handles can get slippery when wet or bloody. The blades and backsprings are thicker in the Alox models, which I like. However, there are downsides...
The Alox knives don't come with tweezers or toothpick, and there's no real way of adding them. Also, the full-sized (3.5") Alox models don't come with a keyring, except for the Farmer and Pioneer.
As for the reamer: it's used to make holes. I've used it for belts and dog collars, but it really shines in the outdoors. I can throw sparks all day long with the reamer and a ferro rod, saving my blade for better things. The reamer comes in handy when the kids are looking for bugs and you need to make holes in the lid of the jar so the fireflies can breathe. LOL. I've used it as a fingernail cleaner on occassion. It does a good job of getting pebbles, mud, and dirt out of boot treads. I use it for a marlin spike (to pick knots apart) when I have to, but it cuts the rope more than picks it. I have no use for the sewing eye that's integrated into it, and have never seen anybody use it. Ever.
If you like the Recruit, try the Spartan. It has everything the Recruit has, plus a reamer and a corkscrew. The things you can do with that corkscrew.... but that's a different thread. The Spartan will run you about $14 in stores.