If they do buy SIGs, they need to make sure they get the newer stainless slides like the P229s have.
I carry SIGs and a Glock daily. I like both, though the SIGs took some getting used to as I had carried Glocks for a few years prior. My only complaint about the SIG is their horrible tendency to rust, at least on the older weapons.
Carry an older SIG in the rain. If you do not PROMPTLY wipe it down as soon as you get somewhere dry, it will rust up. The newer P229s with the blued stainless slides do not seem to have this problem.
We use P220s for tactical stuff. At training or call-outs, the first thing everyone does is wipe all of the extra oil off of their P220s, because if it is not covered in oil before it goes in the case in the trunk of your car, it will be covered in rust when you take it out.
Never seen rust on a Glock. The SIGs shoot fine though.
As a side note, I always shoot a higher score with my subcompact Glock back-up gun than with my SIG duty gun. Weird.