In 45 I own the standard USP, Tactical, and MK 23... Here’s my take on it;
The MK 23 was a gun that was built to a spec set out by SOCOM. From what I understand, not much input was gathered from the people who would use them when the specs were created. It’s a very large gun that is built like a tank, and SOCOM got exactly what they asked for.
It seems like when designing the USP tactical, HK took their learnings from the MK 23 but actually got input from “trigger pullers.” The match trigger on the tactical is infinitely better than the MK 23, and the combined safety/decocker is much more practical in my opinion.
The general consensus is; if you’re looking for a handgun that will survive the nuclear apocalypse, go with the MK 23 (not to say the Tactical wouldn’t survive, but I don’t know if it went through the same stringent testing as the MK 23). Also, if you really have an itch for a MK 23, you won’t be satisfied until you own one. If you’re looking for a good shooting gun to use for carry or competition, then I would say the Tactical is a great option as the match trigger is so much better.
For what it’s worth, I bought my MK 23 a year or two ago used on Gunbroker for $1900, so maybe $2200 isn’t out of the ballpark for a new gun.