My personal experience was (in acquisition order):
a) USPc9 stainless steel.
b) USP9 stainless steel.
c) USP 45 Expert.
I love the Expert, the gun is scary precise, makes you feel like a way better shooter than reality. The USP9c is used frequently due to its small size.
The USP9 on the other hand... almost never see action.
So if it was me, I would try to get an Expert before a USP9c (as the trend is that the Experts are getting hard to find). That being said, the Expert is a *huge* gun, make sure to try out one before buying.
Well I'm loving my HK45c and I plan to carry it a good bit once I function test it enough. However I'm REALLY after a nice USP 9mm compact.
For me, the HK45c and the USPc .45 aren't substantially different. So if I'm carrying a gun of that size, it's always the HK45c. The USPc is a house gun. Since you're looking for a small 9mm, you might want to take a look at the P30SK or the P2000SK.
Well I'm loving my HK45c and I plan to carry it a good bit once I function test it enough. However I'm REALLY after a nice USP 9mm compact. But I'm wondering if I should get the full sized gun first. I want both but my thinking is if I get the compact first I might not get the full size because it really doesn't serve much use for me except for a range toy.
If you are going to carry that - then carry it. If I was limited in my options, I wouldn't buy two carry guns. I'd rather have one carry gun and one range toy. to me, my 1911 and Mark23 are the most fun at the range. I could shoot my carry gun all day there too but the other pistols are just more enjoyable.