I have no experience with two of your candidates but I have a lot of respect for the Glock 27. I have never cared for the feel of a H&K and I find their operation complex compared to Glocks. I am honest when I say that I have never had an oportunity to fire a Beretta 8040.
The Glock 27 is a little pistol that can do it all. It shoots beyond what its abilities should allow. With a Glock 27 you can use a Model 23 barrel, a 357 Sig barrel, I am not sure about 9mm barrels (I haven't tried it), and you can buy an A&G grip adapter and use it with Model 23 magazines.
If you try the A&G adapter you will swear you are shooting a Model 23. I do not find the Glock 27's recoil bad. Now when you get to shooting 357 Sig in a Model 27, with a 357 Sig barrel it will get your attention.
Regards,
Richard.
[This message has been edited by Richard (edited October 04, 2000).]