Bought for my wife to take a 1,000 rd training class. It is a great 23c if I carry can be made a 23 with a barrel I have. The only problem with the compensated guns is they need the front sight wiped off more . The do give old hands a break also.
I had a 19C/3 for a while. I got it because I thought it looked cool and would make a big difference shooting it.
I couldn't really tell any difference in recoil, muzzle flip, or split times. I'm not saying it wasn't there, I just couldn't tell.
I only shot it once at night and I couldn't see a difference in the muzzle flash.
But it was noticeably louder. You could actually feel the report in your sinuses, especially if you shot it from the hip one handed (the first string of fire for our Department qualification course). You could easily tell when it cracked off on the line. A guy on my squad carried a 17C/3 and you could feel the report through your ear protectors.
It made the gun a little dirtier after a range session; the front sight and the inside of the of the dust cover got a little more burned propellant debris than non-compensated models.
It was a cool gun because of the way it looked but I don't think it was appreciably better than a non C model.
I have a Taurus 85 Total Titanium with ports. It kicks like a mule. The ports help prevent muzzle flip but that causes the recoil to come more straight back in to the web of the hand. I think it actually increases felt recoil because less of the recoil is absorbed by flip.
Compensation is different than a brake. If I understand correctly the compensator mitigates flip (muzzle rise) while the brake mitigates actual recoil by redirecting propellant gas in opposition of the muzzle blast. So, the C models shouldn't really have less recoil, just faster recovery time.
I bought a 23c at an auction a few years ago. It also had an aftermarket 357SIG barrel that I really like. The original 40S&W barrel sure blasted out flash and if I was shooting inside in a booth, I would get peppered with debris too. So it was necessary to have full coverage glasses. It didn't seem to matter as much shooting outside. I picked out another aftermarket 40 barrel so if I'm going to shoot indoors I'll use the non-ported one. But 90% of my shooting has been with the 357SIG.