The USP45 Tactical has these features over the USP45:
Threaded barrel w/ O-ring
Adjustable sights
Loaded chamber indicator
Match trigger w/ adjustable over-travel screw
Match hammer
Extended magazine base plates
**Slightly longer recoild guide rod
** I have no clue why, but I put the two side-by-side, and the USP45 Tactical's is longer than the USP45's...???
Other than that, everything's pretty much the same. If you had to choose just one, I'd go with the USP45. You'll save about $400, and have pretty much the same gun.
But, if you're looking for one of the best tactical pistols out there, I'd look no further than the USP45 Tactical. I know that it's just my opinion, but how can you look at this and not like it?
Again, my opinion is just that...my opinion. Not everyone will agree with me, and that's perfectly fine. I love my Tactical, and it is an absolute joy to shoot.
Good luck...