I own an HK45 and have shot my buddies' M&P compact 9mm and Beretta 92FS fairly extensively, and have shot another friend's CZ every now and then. I should probably add that I'm fairly new to handguns, and feel as though I am still learning a lot about how to shoot whenever I go to the range.
I don't even think 9mm has recoil to be perfectly honest. I can empty my friends' 9mms in a second or less, and have a fairly tight groupings of less than 5" in diameter at 9yards.
The HK45 definitely has some recoil. I can't empty the mag and maintain a tight grouping like that (yet, at any rate, I'm getting better though), though the grouping is still easily all in the CoM at 9 yards. I have also observed some of my friends develop a "flinch" type reflex when shooting it.
There definitely is recoil, but with practice, and patience, it's easily manageable. I had to review and experiment with different grips and stances to gain proficiency with it. With a 9mm, I was able to start placing bullets on top of bullets without really paying much attention to grip and stance, and although my shooting with these guns was very precise, I should point out that it wasn't extraordinarily accurate.
OH, and one last thing, HK sights are different from most other sights, and when I figured this out, my shooting significantly improved. You COVER the intended point of impact with your front sight, don't "bob" the target. If you start to "bob" your target, you'll find that you are always shooting low. I noticed a big improvement in accuracy when I adjusted my sight picture accordingly.
I really enjoy my HK45, I would recommend that you get it, especially with such a great deal on one.