In my experience...
Sig feels "smoother handling" and the trigger in double action (hammer decocked) is heavier than Glock. Single action trigger pull in SIG is lighter than Glocks stock trigger.
The low bore axis of Glock will help with recoil, provided that you choke up on the weapon as much as possible (minimize the distance between the top of the web of your hand and the slide). A lower bore axis means the pistol will flip less or have a less jumpy attribute to it if you grip it right. This means faster follow up shots.
The trigger reset on the SIG is OK. Trigger reset means that after you have fired a shot, it's the distance that you have to let up on the trigger before it sets it self again and you can make another shot. The trigger reset on the Glock is great, one of the best out there because there is actuall a tactile feel of it resetting and a "click" that tells you it's ready to go bang again. Once you learn how to use the trigger reset on a Glock your shots will be more accurate and fast because there is a minimal amount of travel to make before making the gun fire. Again, this is one of the reasons why Glock is among the fastest shooting platforms behind the 1911 and maybe the P7.
The grip angle of the SIG is more traditional while the Glock is more aggressive. If you are familiar with other platforms like 1911 and HK then it will be very similar. Glock, hard to describe, I believe that for the person used to the above it will point lower at first.
Weight is usually a big factor in shooting a weapon but because SIG frequently uses alloy frames, it's kind of close to Glock's polymer. Grip size is vaguely the same if you are comparing apples to apples (double stack 9mms for example).
Again, the SIG feels more like a high quality weapon, more smooth and better made. Glock feels a little more clunky and cheap but by no means does that not make it a fantastic weapon. Both pistols will be more accurate than most shooters, but people will probably report that SIG is more accurate because of the lighter single action trigger and their familiarity with the grip angle.
Of the two platforms, I prefer Glock for a lot of the reasons that Demi mentioned (in his post above my last one, it sure sounded like he was specifically talking about Glock characteristics to me). If I were to go for a traditional double action pistol, I'd choose HK over SIG for a couple reasons but I'd feel absolutely well armed with a SIG. 100%. That's why I say it's tough to go wrong here.
Also like Demi said it's how they fit YOU and how well they work for YOU that matter. I would highly advise against buying either without shooting them both, side by side if possible.
cheers