FYI- the three guys mentioned that shoot for Team HK used to shoot Berettas. Their PD switched to HK as the rest of their swat toys were HK too. One of them told me that he is really more comfortable with his Beretta. They are all good shooters no matter what they have in their hands.
For IDPA SSP, I shoot a Sig P226 and do just fine. I also shoot it in IPSC Production class and can't complain there either. I actually started IPSC shooting back in 91 with a P226. I agree that Glocks are probably the gun of choice in IDPA and IPSC in SSP and Production. I own Glocks myself. I have just had better luck out of Sigs, for reliability, mags that drop out when they are supposed to, and not being finicky about reloaded ammo.