Don't buy a phone based on how fast it gets updates. Look how long it took Verizon to push 2.2 to the X and then it turned out so buggy that another update had to be pushed out last month.
Just enjoy the phone. If you want 2.2 now, research on rooting and installing custom ROMs. Otherwise, be patient and let it come. The Fascinate has a GPU that makes the Droid X's look like last gen hardware. It's your decision.
If you have the money and its going to make YOU happy then do what you want man! Updates come when updates come that's just the nature of the beast. I would say do whatever makes you happy. It is your life after all !