While I do not now own either I have owned both Glocks and a Sig 229. At the risk of getting flamed here are my thoughts.
Sig 229:
Pros-
-Well built gun.
-Extremely reliable.
-Very accurate
Cons-
-Terrible trigger, I know that the Sig fans will call me crazy, but the trigger sucks. Very very heavy DA pull, overly long reset, and an OK SA pull.
-Feels totaly top heavy, with the grip being thinner at the bottom but wider at the top. Not a good feeling grip by any gague. The top heavy feeling was the thing that bothers me the most about it.
-Erganomics are bad if you shoot any other guns. If you shoot nothing but Sigs you would be fine, but if you shoot anything else it will foul you up. i.e. slide release is where the decocker should be and vice a versa.
All in all Sigs are overratted im my humble opinion Flame suit on.
Glocks:
Pros-
-Extremely reliable
-Nice simple design.
-Easy to disassemble and field strip for cleaning.
-Accurate for most jobs.
-Trigger is good once mastered short reset is great.
-simple manual of arms.
-Do not have to worry about hurting it.
-Grip fits me like a Glove
Cons:
-Ugly. Although you do not have to worry about its looks.
-not as accurate as other designs. at least for me.
-Ugly
-Cannot change grip of you do not like it.
I may get another one. I kind of miss my G23 although I do not miss my 36 or 27. If I get one it will be a 10mm for field use. I wish they would make a single stack.
All in all I prefer the 1911 to both of these designs. I will never own another Sig, unless it is that trailside .22, I really want one of those.