Congrats on the new purchase!
I'm sad to say I'm with you on the Glock 21SF. Mine "went away" the other day, never to return, and I'm not missing it. As much as I like the 9mm and even the .40 Glocks, their large frame guns just don't inspire me in the same manner.
How's the HK's reliability and accuracy so far? I've never shot a LEM-equipped HK, but you're not the first person to say nice things about them.