I am a a new product development engineer, a mechanical designer, I can say the FX airguns - Impact in my case, are impressive piece of engineering. You can just grab it and go shooting, or you can grab it and start tinkering.
Do you remember a Lego time when you just grow out of diapers?

My younger son is 25 now but when you enter he's quarters - a first impression - there are tons of money in he's Lego projects and some really impressive gizmos, we/he didn't throw away years ago but all behind a glass display and on shelf's.
Like with anything, look at the cars or coffee makers or ...I don't know...tablets, or ...airguns. On total volume of sales a satisfied majority will not come to a forum to give a five star, but people with problems will come and will asking questions. Plus to add there bashers who don't own one but addressing a very important voice. So a keyword search for FX ads up the total hits.
The most of the problems you can read here are coming from people wannabe a mechanic, want to tune but don't know how or already screw it up at a very first corner, or, want to go to a next level upgrading.
What you like more? to be a mechanic or go shooting? You can do both...
The FX Facebook page have 42,376 followers, btw.