My Father loved his, however I have never shot it. I just sent it into Glock and they upgraded to gen 3 frame and went over it.
Will be getting back in a day or two and then will test it out.
By the way, Glock customer service is top notch. They both called and emailed with questions about switching to an SF frame (which they could not do because then it would be considered a new gun) but anyway, getting new frames for G21 and G20 and all updated internals and can't wait to get them back!
Go with a Glock, but I did consult with them on using the G20 for .40, but they of course did not recommend doing and would void any warranty. I'll just keep it running 10mm.