When you're asking how they compare, are you looking for answers concerning durability, crispness, feel, lock time or repairability?
I have a set of Kolar triggers that have over 100,000 rounds on them and never had to do anything to them beyond cleaning. It took a short time when the gun was new to adjust to the "feel." (I'd been shooting Perazzi previously)
Lock time, about average. (my opinion)
Have had several sets I really liked for the crispness and "feel". Have broken several hammer springs, but takes 5 minutes to fix. Perazzi makes a good trigger system in my opinion.
Lock time, about the same as Kolar as far as I can tell. No sure anyone can discern the difference in lock time between the two.
I have two Perazzi's: a Comp1 with a Precision Gold double release and a TM1 with a converted release trigger. NSXER there is no comparison the Precision Gold IS hands down a much better trigger. My tax refund check will be "spent" to get a Precision trigger for the TM1. Contact Randy or Diann at the above link and don't look back. If you want the BEST trigger for your Perazzi click on the above link and don't look back. The Precision trigger is crisper.. faster more durable and easier to maintain than ANY after market Perazzi trigger. Moreover, you can sell the original trigger to re-coup part of the cost of the Precision.
I have owed several Perazzi MX8 style guns, K80 and a Kolar. I really can not tell you about lock time but I can tell you about slack in the trigger and trigger pulls. My Kolar has the crispest and lightest of them all and I believe it helped with my flinching problem. The worst of the bunch was my MX8 bunker gun. I had Giacomo give some of his magic but there was something still wrong. I now prefer Kolar and might be buying another in the future. Mike