Holsters are the main factor, I haven't found a good range/ranch, off duty/non tactical holster that will fit the high profile ft sight without having to custom make one.
FWIW, I got the leather Don Hume holster (also on TGS website, ~$45) for the USP45 and worked the living **** out of it. I would work the leather with my hands while watching Tv or somethig. I also would wrap my pistol in the plastic wrapper it came in and work the gun in and out of the holster, then leave i in there for days. After all that it works quite well for my USPT40
I actually bought it for my USP45 Custom Combat, which came with a Novak front sight from the facotry that also sits higher than a regular sight. What a PITA to find a holster fo that. I figured because of the properties of leather I would make it work and it does. It actually works better for my USPT though because of the angle on the front sight allows it to slide out easily.
ETA - That same holster fits my P30L like a glove... almost better than the USP.