Is it worth the extra money to get the compensated version of the Glock 31 or 32.  I have heard that it helps the muzzle rise, especially on the .357 SIG round, but does it help enough to spend the extra money on it?

When I got my 32, all they had left was the 32C where I got my pistol (when my PD switched to the 31, everyone bought up the 32's real quick).  I rolled the dice, and have been very happy with my 32C.  You will hear many people decry the comped pistol, but I have no problem with it.  It doesn't blow your eyeballs out or catch your face on fire when you shoot in gun retention/close quarters positions.  The comps make little to no difference in the flash at night (you still have some blindness from the flash, but it's just in a v-shape instead of a ball).  The day I got my 32C I shot the highest score I'd ever shot on our PD's timed qual course (which is a 50 shot course from 1 to 50 yards, includes close combat unsighted shooting, mag changes, strong and weak hand, barricaded, etc).  I have had the pistol for about 1 1/2 yrs, and not a hint of a problem.

The 32c is well worth the extra few bucks.  I have shot  it next to many 32's, and the muzzle flip is significantly less.  They are good, reliable, accurate pistols.

Good luck.

The 357SIG doesn't recoil that bad if you practice.  My only issue with comp/porting is that it reduces velocity.  

Quoted: The 357SIG doesn't recoil that bad if you practice.  My only issue with comp/porting is that it reduces velocity.

Agreed - but the recoil is almost non-existent with the ports.  The muzzle just doesn't rise (there is more of a straight-back push).  It is loud, though.

On the velocity loss - took this pistol (32C) to a terminal ballistics workshop where we killed a lot of jello (ballistic gelatin).  We chronod every shot into the gel.  One of our guys brought a 32.  We were coth using our issued Speer 125gr gold dot ammo.  There was almost no difference in the velocity (something along the line of 10-20 fps), and the performance in the gel was identical.  The penetration and expansion was so close, that it was not worth losing a second's sleep about it.

Also, I was surprised to see that this load penetrated and expanded to the same diameter as the .45 round we had just switched from (230gr Gold dots).  Goes to show that the guys at Speer really have done thier homework on the bullet construction.  I really came away from this course/workshop with a newfound respect for this caliber (we also shot our issued 31's, but no 31c's available).  I had bemoaned our switch from the .45 to this caliber, but I am more than OK with it.  I now only carry my 21 for search warrants (leaving it in my SW kit bag).

I own the Glock 31 in .357 sig. I would say get the compensated and have fun with how accurate you would be while shooting it and then if you want non compensated just purchase another Glock factory barrel for around $120.00 dollars and shoot it like a regular gun.