HK has made many pistols with different actions.
USP series...many sizes, many calibers, options of DA/SA with cocked and locked/decock or both, SAO, DAO. Blocky, accurate, and super tough and reliable.
P2000 a compact and more ergonomic version of USP, came in 9mm, .40, and I believe .357 SIG. Triggers came in DA/SA, DAO, and LEM versions, I found the LEM to be like a single action trigger with long take up and short reset after first shot.
P30 series. A larger gun than P2000 with even more ergonomic changes....multiple grip panels. DA/SA, LEM, and DAO triggers. I found the triggers were inferior to USP DA/SA triggers due to very long take up.
SFP/VP9. Striker fired gun. It was compared favorably to Walther PPQ. I find it big for what it is.
HK compared to glock is bulky for what it is but very reliable and accurate (I also find Walthers to be larger than comparable Glocks). My favorite is the P2000 but I like small guns. If they ever made a polymer pistol in single stack I would be interested.