The lack of second stage in the trigger and the paddle switch
Can't you just screw your Cougar handle into the base of the Warthog?
If you can find a modded Cougar, btw, it is worth EVERY penny. Or, get a used one and then get IJ's Uber II NXT mod:
http://frugalsrefugees.yuku.com/topic/274/Mods-and-Tweaks
I was talking about the CH Fighterstick with that quip, not any of TM's F-16-based sticks. The F-16 FLCS, F-22 Pro, Cougar, and Warthog all have the second trigger stage and the paddle switch, though the Warthog's is easily user-removable for the sake of A-10 purists.
From what I've heard, the Cougar handle is indeed intercompatible with the Warthog base, but I can't directly confirm this due to not owning a Warthog, and I can't be bothered to sell my FCC-modded Cougar stick (also with those replacement screws) + Hall sensor/UTM-modded Cougar throttle + Hall sensor-modded RCS to afford one in the first place.
(I am curious as to what the U2-NXT feels like, though...since you're also living in Georgia, maybe I'll get the chance one day. In the meantime, I put up with the lack of buttons and switches on the MS SWFFB2 as my deflecting stick of choice.)
Also, there's someone in the Buy/Sell/Trade subforum here that still has a Cougar to sell, if anyone's interested...it's stock, though.