Sigs aren't any more durable or reliable than Glocks. I would definitely take that trade as a P229R is worth more than a G30, is a nicer gun overall, and is a little bit more accurate.
Sigs will give you a external thumb safety, Glock won't.
What model comes with an external safety? Except for the mosquito (which isn't really a SIG) I don't know of one. Maybe a P210?
There are single-action only versions of the P220 (I have one and absolutely love it!) and P226 (haven't seen one, and they're apparently meant for competitive shooting). Both have a safety that's really similar to a 1911 with an ambidextrous safety, except that you can rack the slide with the safety on, and you can set the safety with the hammer down. The second one isn't all that important, but it sure is nice to be able to set the safety before loading the pistol.
What model comes with an external safety? Except for the mosquito (which isn't really a SIG) I don't know of one. Maybe a P210?
EDITED: Wish I was that quick with the edit button.
While it is true that most Sigs do not have safeties on them, after a quick look at the Sig sight, there is the Mosquito and P210 that you noted as well as the P238, P226 X Five and all the Sig manufactured 1911 type pistols.
Not many, true, but still there. Glock has no Frame Mounted Safeties. Just the trigger, still better than nothing but I would like a FMS, but thats just me.
Cheersatriot:
p250 is DAO with smoothed down hammer,double strike capability.....not striker fired.