For intensity of inversions on B&M inverts, and Better airtime (usually) on sit downs then back row.
Personally i still prefer the front, especially on Launch coasters as with the wind blowing right in your face the launch feels like twice as forceful, although on rides like stealth sitting in the back gives you some great airtime which you don't experience on the front, so i try and do both. B&M inverts i still enjoy the front more as i like to take in the surroundings as i ride and see where i'm going rather than being chucked around in the back row (not saying i don't like the back row, just prefer front)
I always try to ride the front or back row, failing the 2nd or 2nd to last row, failing that i get annoyed and usually don't enjoy the ride lol!! :roll: