It is roast beef and it is sliced in store. It just is packaged the same way turkey breast is packaged in deli's. They add a few roasts to a bag that are trimmed up of fat, bone, and gristle. They then vacuum pack the roast and it gets steam cooked in the bag. This causes the meats to weld together and form larger roasts or tubes of roast. It is not however frankenmeat.
I mean has anyone ever looked at the giant turkey breasts in the deli section of stores and sandwich places? Notice how they are about eight inches across in all directions and very long? That is because each package is 2-3 whole turkey breasts that went through the same process. No turkey has breasts that big.
Arby's has its problems because it is somewhat limited menu wise. Where it is not limited, it is expensive. Plus I can not recall much of a dollar menu which other places have been really ramping up and pushing.
They are very decent in my opinion. They just are not recession food and most people recall in their minds high prices, even though you can get 5 roast beef sandwiches for 5.01 plus tax (could be 6.01). I just know anything but the base roast beef sandwich costs much more. Be it the ArbyQ, the cheddar arbys, and other sandwiches.
I really like their sauces and their mocha shakes myself.