I have been playing with extended frames for about 15 years. First with Dunlop 200G + 1 and then to the Pure Drive +, AeroPro Drive +, Storm Tour +, and now with Pro Kennex Ki5x. Babolat has been extremely successful in offering these choices, but they also have fewer lines of frames than other companies. Most other companies don't offer extended versions. Maybe its just too much of a hassle and the stores don't want to carry that many options.
As for myself, I have always enjoyed the extra reach on my serve and backhand. For my forehand it doesn't really matter which I use, but I do get more control with standard length. At the net, I do prefer the maneuverability of a standard frame.
Altogether, I feel that my backhand is significantly worse with standard frames since I already hit near the head. For all other aspects there are differences but all relatively minor and therefore I choose to stick to extended.
After 15 years of playing with extended racquets and since I am starting to play more doubles, I am now willing to consider going back to 27" frame. I have yet to find something that is as good as what I am playing with now. Personally, though, I prefer 27.25".
Ex-Coach: U of Delaware & Drew U. Pro Kennex Ki-5(R) & Gamma RZR 98 (L)
Dunlop Black Widow 17 (63lb) Babolat N.Vy 16 (64lb) USTA 4.5.