Does the AI provide an excellent challenge? Does it do a good job of setting line-ups, trading, draft picking, determining strategies, etc?
OOTP, according to some of its long-time players, can be dominated by taking advantage of the trading features in that game. A few smart trades on your part = perennial dynasty. From what I've read in those forums, once you learn the system, you can take a last place team in every category and create a superstar franchise in only a handful of years.
I'd like to buy this game, but if the above is the situation, I'll wait.