I shoot IDPA and Steel Challenge with a Glock 34. I had a trigger job done and put a new fiber front sight on and a Defoors Tactical rear on. I run mine with a Brooks Tactical Agrip and have Vickers mag base plates on all my mags. This is a great setup and is perfect for IDPA.
Another good thing, I also carry a Gen 3 G17 so my mags can be used in both guns and the G17 and G34 share the same frame so there is no 'separate gun' I must learn for competitions. Also, both use the same round, 9mm, so I'm not buying a second bullet type.
I also own the 5.25 inch XDM in 9mm.
It feels better in my hand but I shoot the Glock better. I also don't like the rear site on the XDM. I do like how the XDM comes apart though. I hate those takedown tabs on the Glock. Kills my fingers.