Okay I'm no expert. But here is my opinion. Not worth anything, but may help.
I've had pro circuits, t5, t6, fmf gnarlys, LRD, PT mid, PT high, CPI.
The CPI are on my bike now. Ported 4 mil. I love them perfect for me and my riding. A great top end pull and still plenty of low end for the trails. The front end comes up on command the first 4 gears. Can get sketchy fast. But a good time.
On my girls bike there is PT highs. Awesome pipe. Make the bike pull like a 4 stroke. Not impressive on a drag race or WFO run. But tight trails and out of turns the power is instant. All while remaining smooth. No hit that yanks and tugs on your elbows.
The other pipes were all fairly similar to each other. Had a little more rev with the t5 then the fmf or LRD. T6 were okay, were actually pretty loud. Pro circuits were on my bike when it was really stock. But the bike ran well for a stock bike. LRD I wasn't a fan. They were the adjustable. Never ran good on my bike. And the fmf were okay too. Just made the bike more responsive. And louder.
PT mids. Just as bad ass as the highs. PT are great pipes and make the bike really rideable.