The P30 has the best grip of any pistol anywhere ever. Make sure you figure out which trigger variant you are trying out. People have their personal preference. I prefer the Light LEM trigger on the P series pistols.
The trigger on the USP is way better. The USP is....bulkier. It feels like a battle pistol that can take a direct hit from a bomb and keep going. The P30 doesn't have that same feel but it is still stupid reliable. The P30 L should have the metal bushing on the guide rod now. The P30 is a great pistol, with very light recoil, and it's even better on the longslide version. Get it, you will love it, I promise. If you really want one, this is an OUTSTANDING deal on the hkpro forum:
A P30L, Light LEM with Gray Guns RRCP Package AND Heinie sights? Uhm, yes please. I have the Gray Guns RRCP package on my P2000SK and absolutely love it, it makes a world of difference. If you get this and for some reason don't like it, I will buy it from you for what you paid.
WTS: Grayguns P30L 9mm Light LEM (no safety) with Heinies
That is a bargain! What's the best way to go about checking out the different triggers? I've owned a USP45CT with the da/sa triggers but have never tried the LEM that everyone raves about. How does it compare to a Glock trigger? They are able to be converted from one style to another, correct?