I only played Tyler once but I completely agree that splitting it up in to two courses and adding nine is the way to go. I haven't played many 27 hole courses but the ones I have played often give you the feel that it runs on too long, mostly due to a lack of diversity in the terrain and hole types. I'm not saying Tyler has all of this but most of the course has the same type of atmosphere so after 36 holes you get that feeling.
As two seperate courses you can play one, take a break and come back and see it as a completely different course. I think just the mental aspect of that will make it an even better experience overall than it already is, and it's already great.
I'd also add that permanent long baskets on some of those long holes would of also made my experience much better, having to play a 200' hole then walk the other 500' of it is a huge part of the little negative feedback I had for the course.