I have both. The 3.5 lb Competitive was my first TriggerTech and it has a very short take-up in the first stage, has zero creep/grit, breaks like a glass rod, has zero over travel, and an extremely short & positive reset. As someone used to the LaRue MBT-2S for my precision guns, the Competitive feels like an upgrade in every way (though I do still really like the LaRue's wide face). I don't think that the MBT-2S is lacking in any particular way - just that the TT is much more refined & precise. I haven't tried other drop-in triggers, but prefer the TT 3.5 over Geissele SSA/E & LaRue. The short first stage took some getting used to, but if you like shooting 1911s, you'll find it very similar: minimal take-up, a brief wall, then a very precise break. The reset feels similarly light, whereas the LaRue & Geissele have a much more pronounced reset.
Because the Competitive has "frictionless" release technology, the pull weight feels lighter than I expected. After running a few magazines through my SPR, I didn't really think there was a need to go any lighter than 3.5 lbs. But I was curious about the Adaptive, so I picked one up for my large frame 6.5 Creedmoor. I set it to ~2.5 lbs, and the light pull weight is definitely appreciated for a more precision-oriented bench gun. I haven't adjusted mine heavier than 3.5 lbs yet, but suppose that could be an interesting test for those that prefer heavier pulls.
For me, the Competitive is as light as I'd ever reasonably need it to be for precision use, while still feeling safe enough for use in a defensive role. The Adaptable (or Diamond) would be worthwhile for anyone looking to gain an extra edge for competition. Personally, I prefer curved triggers over the flat face, but the flat TT is growing on me. I'll still use the MBT-2S for my general purpose rifles & pistols, but plan on using the TT Competitive for my ARs with mid-powered magnified optics.