I own both a 627-5 and a 929. I use the 627 for steel, since it wears a red dot the shorter sight radius is of little consequence. I use the 929 for Icore & USPSA, to take advantage of the longer sight radius with the open sights. Since you are shooting open, and using a red dot of some sort, the longer sight radius of the 929 offers no real advantage, while the 627 will clear a standard holster a tad quicker. If you are using a race style competition holster (think double alpha racemaster) then the shorter barrel offers no real advantage.Since you are not reloading "on the clock" the 38 special cartridge is fine, no advantage going to the short colt version. One consideration would be the cost of the ammunition. If you reload, then the cost for either the 9mm or 38 special would be the same, but if you don't reload, then the 9mm would probably offer the advantage of cheaper, and possibly more readily available ammunition. I personally don't much care for the looks of the 327 TRR8, but the top revolver shooter in our local steel league uses one, so I wouldn't rule that model out either. Again, if you are using a race holster all 3 (327, 627 and 929) will fit the bill. If you prefer a conventional type holster, the 327/627 shorter barrel might be a tad faster in the draw.