Sorry for the late reply; I work a late shift, and my reply to your question will take more than a minute or two.
I recommend first making a backup of your phone as-is, then flash either CTMod, or the current Megatron, make a backup of that, then flash the other, to see which one you like better. Regardless of which you stick with, you can always flash the Megatron update when it comes out, as it sounds like it will be a full ROM, and not just a patch.
As for goodies, there are plenty of themes for Megatron, including my own Red-n-Black (which I'll be porting to CTMod, as well). I also have flashable baseband updates, and am working on a theming guide if you'd like to try your hand at making your own.