I finally got the LEM trigger kit, that has been on back order everywhere, and did the swap in my USPc 9mm last night.  I have a P30L with the LEM and love it so much that I had to change the USPc.  Took about 45 minutes following along with a video on Youtube where the guy was doing a USP 45c.   Just took my time and it wasn't too bad.  My gun is a 2016 date so I left the trigger spring and hammer spring stock.  I've heard that the trigger spring swap is a PITA so I'm glad I didn't need to do that.  I'll get to run out after work today and put a few rounds through it to check for function but just dry firing it seems to work perfectly.

I like my p30 lem as well. It's one of my colder weather edc. Really like their match trigger on my usp45t too good stuff

Everything functions just the way it is supposed to.  Put 50 rounds through it this evening and it went bang every time.  The new hammer seems to be a little off to the left of center as quite a few others have noted on their LEM conversions.  It doesn't seem to affect anything so I'm not gonna worry about it.  I probably wouldn't have even noticed had I not read about it before doing the conversion.  Anyway...I'm quite happy with the outcome!

I converted all my USP's to the LEM kit, don't be afraid of changing the trigger return spring, just get the special plyers and have some patience.  I prefer the light trigger return spring but I know others who prefer the medium and heavy.  Its a personal thing.  If you converted yours from DA/SA, it is likely the light trigger return spring was the one in already place.  I run a 12# wolf hammer spring in all mine, and it improved things quite a bit with no reliablity issues at all in many thousands of rounds.

USP/c LEM is by far and away my favorite pistol.

I converted both my USP40C and mu USP45C while watching the video. The 2nd one went much smoother.

What sort of "special" pliers are needed?

Google Trigger return spring tool.  It’s just a needle nose plier that has a round space ground out for the spring.

You can also get a cheap set of harbor freight hemostats and grind a round spot out near the end for about $3.50 and 20 min. They work.