I've heard bad things about the Mbox 2's preamps. Thats all I know.

I have heard nothing but bitterness from Mbox owners.

I use an Mbox2 Pro and have made records on them.. even mixed a song on one that was top 40 on radio. Therefore I conclude for my self that it is useful. your mileage may vary.

The big question here is do you want to use Pro Tools?
If yes, then you have to buy some kind of Digidesign interface.
Pro Tools is the most widely used recording program in the world.
Somes likes it and somes doesn't, but one thing is for sure, a LOT of recording gets done with it.
M Box Pre amps are no worse than anything else you can get for the same price. (Keep in mind you are also getting AD/DA and a full featured standard of the industry program) You can always buy a nicer pre to use with the M Box if you don't like the on board ones.
Presonus make good stuff. You won't be sorry you bought it until you spend a whole lot more money. You will still have to get a program to go with it unless you can get by with Cubase LE which is usable but limited.

All due respect but, ProTools LE is also limited. That would be the L in the LE. Max 16 simultaneous inputs Max 32(?) Audio tracks. ProTools LE is no less limited than Cubase LE. Don't get me wrong. I like ProTools LE but I also use and enjoy using Cubase.

Cubase is no less capable of producing good quality results than PT. It's true that a majority of studios us PT but there are plenty of pros here who choose to use something else. ProTools is not the only option. For a home user I think cubase is much more intuitive. ProTools routing system was designed for people who are accustomed to using a hardware mixer and patchbay. Most newbs will likely find it confusing without a good amount of reading. Not that Cubase or other software are any less complicated but you don't have to think as much about the signal path with other software. The signal path is incidental and is not so much as implied(unless you specifically are routing for a purpose) in many other DAWS.