I do agree 2 buttons are preferable to 3, but it all depends on what you're doing.
If I were going to a wedding, I wouldn't wear a 2 button. Likewise, if I were in law school and had to dress to impress, I wouldn't wear a 2 button either.
The thing about three buttons is that they can also be interchangeable with tuxedos. So it's win/win. Every man should have two different suits for totally different occasions.