I have nothing wrong with it, but as the 'honeymoon stage' is an average of 2.5 years long, I'd always suggest leaving it 3+ years before making commitments which could later appear to be mistakes.
No matter how much you already know about your other half, you will continue to unearth new (pleasant and unpleasant) things throughout your lives. Therefore the longer you leave it, the more educated your commitment will be. There is no need to rush into things. But then again, if we didn't rush into anything, we'd never make any progress! It's all about finding your balance, which will be completely different between you and the next person.