I've read all the forums you have read Alpining. I was on the fence for a long time on compensators effect in 9mm blowback rifles... Until I did actual real world testing of a few different compensators. I've tested the gamma, the Tandemkross, the Davinci, a few linear comps, and a few traditional side and top ported 9mm comps... And through all that testing I noticed a distinct noticeable difference on the muzzle rise and dot bounce on the upward ported 9mm compensators. The testing was done in an 18.7" barreled Ruger PC Carbine in a tandemkross upriser angled chassis system with a holosun 510c at 25yrds. Now, if you are trying to control recoil, compensators will not really help you much. But, if you are trying to use them to flatten dot bounce, which is the dot popping around and making the second shot slower to acquire the same impact point, then they do work. I can't measure the specifics because I don't have laboratory equipment to specifically measure the amount of muzzle movement, but in real world application it gives me the ability to make a combination of faster and more accurate splits that are measurable in IPSC/USPSA competition shooting.
Go to a lvl 2 or higher IPSC PCC match...99% of competitive shooters at these matches run a comp. The gains might be micro gains, but when .35 match points is the only thing between second and fifth (as it was at PCC Nationals this year), you will take the micro gains and be thankful for them.
So if you want to spend the money on a comp, and are looking for micro gains to help keep you competitive? Get yourself an upward ported comp like the TK, Davinci, MBX, etc..
If you don't want the micro gains... You do you
If shooting without a comp works for you, more power to you. But trying to tell people who have actually tested comps in real world competition settings that they are "wrong" because of something you read one time in the interwebs? That's called being a troll...
Cheers,
ACD