The story was brilliant but way, way too brief. I was shocked when the credits rolled. I don't know how long the various GTAs are but V has to be the shortest. The characters all had so much more potential.
All gaming is going to way of short campaigns with focus on multiplayer. GTA's no longer the exception.
III was shorter, at least in time it took to beat. You could beat that swiftly. Vice City was a bit longer. SA is the longest, IV not as long. V I think isn't as long as IV and SA but longer than III or VC. Again, I think what makes it better for me is it's extremely replayable.