all dynos are different.. a car that read 200rwkw on one dyno can only read 160rwkw or so on another. I'd like to see any car with a stock turbo pull 200rwkw on a dynologics dyno.
And while I'm not saying all dyno tuners are dodgy, but often if you take a car to a dyno tuner it will "magically" gain that 20rwkw soon as it walks the door. They do have to prove they have earned their money somehow afterall.
Don't take the dyno for gospel, its all about how the car feels to drive afterall. Does it "feel" faster? if it does it probably is.
It seems like he should have got a little more out of the powerFC than you had previously, but all cars respond differently to different mods, and I assume some cars respond better to a powerFC than others on the stock turbo. You are also getting that extra meat in the sandwich between 3000->5500rpm - thats some 10 -> 20rwkw across most of there. That should be noticeable?