Grip-frame angle: Sig's grip-frame angle feels the same as a classic 1911. Glock has a steeper grip-frame angle causing it to point higher than Sig. This is neither pro nor con, just whether the ergos match your hand and wrist. If you point naturally with a 1911, you'll like the Sig. If you point low with a 1911, you'll like the Glock.
Trigger: Sig is DA/SA where Glock is (essentially) DAO. Sig DA pull is 10#, SA pull is 4#. Glock is a consistent 5-6# every shot. The Sig requires practice and training to get consistent accuracy as the trigger pull changes. The Sig trigger is a longer pull, even in SA mode - but it is lighter and smoother. The reset is also longer on the Sig - the trigger has to go about 80% of the way forward before the reset clicks. Glock has a short reset like a 1911 - about 1/3 to 1/2 of the way forward. Overall this is neither pro nor con, just different. Some say the Sig trigger is better for accuracy but Glock is better for speed.
NOTE: Sig now offers the DAK trigger, which is functionally the same as a Glock. Consistent 6.5# pull, no decocker. This is becoming the preferred Sig trigger for duty use for LEOs, military and civilian CCW. Sig also still makes the old DA/SA trigger available, which is preferred by target shooters and old school types.
Durability: both are durable guns and perform about the same in abusive LEO and military tests.
Weight: The Glock is lighter. One would think it would have greater felt recoil, but the lower bore axis helps reduce that effect.
Size: Glock tends to have slightly smaller overall dimensions for a comparable gun.
Bore Axis: Glock has a lower bore axis, which helps reduce felt recoil and muzzle flip. But it is also lighter. Overall the lower bore axis seems to compensate for the lighter weight, providing about the same overall felt recoil and muzzle flip as a Sig.
Capacity: Most glocks have higher magazine capacity than Sigs. This is usually because compact Glocks tend to be wider double stacks where compact Sigs are single stacks. Depending on one's hand size, capacity can be an ergonomic tradeoff.
Safety: neither gun has or needs an external manually manipulated safety. They are designed to be carried with a round chambered, they are drop safe and they will not fire unless you pull the trigger. Glock has their triple safety "safe action" mechanism and Sig has their decocker, locking firing pin, hammer intercept notch and initial DA pull. Two different engineering approaches but the end result is the same: a safe gun that won't fire unless you pull the trigger.
Holster: Due to the lack of an external manual safety, both guns require a holster that completely covers the trigger area. This is really just good general holster design, not a special requirement for Sigs and Glocks.
Hammer: The Sig has an external hammer, the Glock does not. The Sig's external hammer could catch on things, but it also gives you extra safety when holstering since if something catches the trigger you will feel the hammer rise before it fires (assuming your thumb rests over the back of the hammer when you holster, as it should).
Second Strike: If a round fails to fire, you can simply pull the trigger again on a Sig. This is called second strike capability. A Glock has no such capability, requiring a clearance drill (tap-rack-BANG). You can always do a clearance drill on a Sig too (especially if the second strike fails) but second strike gives you an faster extra option to use before resorting to tap-rack-BANG.
Takedown: Some consider the Sig safer since it forces one to lock the slide back and doesn't require a dry fire. But when proper gun handling rules are followed, both guns are equally safe.
Ammo: Sigs and Glocks can shoot any SAAMI ammo including +P. Glocks have a looser chamber with less support especially in the 6:00 (ramp) position. This puts a little more stress on the brass when firing. Glocks also have polygonal rifling which can increase firing pressures, especially with non jacketed ammo. Stick with factory fresh jacketed ammo and you'll be OK. Don't shoot non jacketed lead bullets in a Glock. If you shoot reloads in a Glock, be extra careful to look for brass showing signs of stress or wear.