FC is pretty small. You can do the whole park in a matter of hours. It's nice, don't get me wrong, but it's more of a local OKC park vs. a major destination park like SDC. The coasters are OK, but nothing to write home about unless you are an enthusiasts who geeks out over a rare Schwarzkopf and one of the last Arrow shuttles. They have some shows, some of which are nice, but not on the level of what SDC does.
If you plan go to multiple parks using the discounts/membership it might make sense, but trading SDC for FC alone would be a big step down in experience. SFOT or SFStL are both decent parks to try to hit as well, more-so SFOT.
Personally I feel like almost every other park I visit is a bit of a let down after growing up with SDC. You rarely get the feel at most parks that you are in a warm, wholesome environment. It's usually just rides rides rides and lots of annoying teenagers. I can get being burned out of SDC after a few years though. Change can be good, but there's nothing else quite like SDC unless you head to Tennessee.