What do you want to do with it? the standard USP is very accurate as it comes from the box, and the Tactical is a bit more so. Any good...really good... gunsmith can build a 1911 that will function fine and be more accurate than either, but it will cost you a lot more. If you want to play games, the 1911 is the ticket for IPSC and the Glock for IDPA. The standard 1911s, Glocks and USPs are service pistols and trade off some guilt-edged accuracy for less expense and more reliability. Damned few people can actually USE the difference between a 3-4" pistol and a 1 1/2" to 2" pistol at 50yd. but the difference in cost to shrink a group that extra inch or two is huge, and only obtainable with the correct ammo in a machine rest.
If you get the Tactical, you may or may not have an issue with sight heights if you change them out. I think Novak is making sights for the H&Ks now and they may be able to tell you what issues, if any, you would run into with this.