As Ultimate DO mentioned, your FTX will be 3 weeks long as compared to when I went in 2005, which was only one week (5.5 days essentially). I'm not sure what else you'll be doing, but all we really did was land nav training, M9 qulification, M16 zeroing (didn't even have a chance to qualify...), and a hodgepodge of other random things. Pretty fun time in my opinion. I highly recommend driving if at all possible. My buddy and I drove from Philly and made it there in about 36 (with one 4 hour stop + traffic) hours and drove back in about 28 hours.]
The food wasn't all that bad in the mess hall. I think the USUHS guys got per diem and the HPSP guys got free mess hall access. There's a bunch of restaurants on and off base (another reason to have a car) and a ton of stuff to do on your off time (working out at the gym on base, Six Flags, Austin, Corpus Cristi, Schlitterbahn, Canyon Lake, tubing down the Guadalupe, downtown San Antonio, to name a few...). I had a blast. Bring your sunscreen.
Let me know if you have any other questions.