The top guys are using a glock 34's and Elite II's
with some minor modifications. Mostly fiber optic sights
It also depends on what division your are shooting
SSP/ CDP/ ESP/ SSR
in SSP - the Elite II or Glock 34
SSR - either a S&W 610 shooting .40's or my favorite the 625 in 45acp- both take moon clips and are easy to unload with the shorter brass case, and to make a Power factor of 125 with a 180gr,200gr, or 230gr bullet makes for very little recoil.
ESP - is becoming very popular for 1911 style pistols in 9mm, 40, 38super, 9x23... I have seen alot of guys who will download a 180gr .40 for this, again if set up right very little recoil.
For me I shoot CDP and I like my guns to have adjustable night sights, checkered front strap, checkered grips, 4lb trigger, ambi's, beavertail, and S&A style magwell.
Much like this gun in the attachment