kahuna,
I finished up primary at Vance a few months ago now and am shortly going to Meridian for the advanced E-2/C-2 syllabus. Overall (and in hindsight!) it wasn't extremely bad but it definitely is a harder path for primary than going through Whiting or Corpus. The main difference is at Vance you will be working 12 hour days for a majority of your time there. You get used to it though but it does waste a lot of time; I could never study effectively in the flight room, then when you get home you study for another 4 hours or so. One good aspect of the long days is that they brought you extremely close to your classmates and there was much more of a sense of camaraderie than with the Navy system.
Be prepared for the flightline, you will start at Vance basically redoing API for 5 weeks or so, then all hell brakes loose. The first 15 days are terrible, so much to study, but things slowly get better after that.
As far as the Tweet goes, it is an awesome plane to fly. Things happen a lot quicker than they do in the T-34C so be ready. You will get to do more intense aerobatics and formation flying than the Navy primary guys will.
As far as pipeline selection, it all comes down to luck at the end. Two weeks before I finished up they changed the grading from (70% flying, 15% API, and 15% Air Force academics) to 100% flying which I believe is how Navy primary does it. You are then compared to the last 100 graduates in a roving bell curve and ranked accordingly. Unfortunately different Flights (i.e. the squadrons are divided into 10 or so Flights) at Vance are easier/harder just like everywhere else I guess, but the overall average between the 2 squadrons remains the same.
In the end, all you can do is your best, I absolutely hated Vance going through and just hoped to survive. Historically the Navy has more than average attrite or DOR out of Vance than at Whiting or Corpus. Looking back though (in my vast 2 months of experience!) two things strike me as definite pluses: #1 The Tweet is much more of a performer than the T-34C and is probably the most fun airplane I will ever have flown, and #2 The fact that you went through Air Force primary definitely is an ice breaker whenever you have to deal with Air Force pilots in the future. It gives a common bond if you will, this may sound corny but it definitely helped me in Intermediate when I was flying with Air Force instructors.