Had one for 4 months now, brilliant marker overall.
Initial setup can be tedious but as long as you read the instructions properly and break in the reg you'll be fine.
Got mine imported from the US for £300 including vat and delivery, the delivery took 3 days as well.
Delrin bolt stock, pipe barrel (near enough) stock, detonator reg stock.
Cam feed system is supoib, it's physically impossible for the marker to chop.
Trigger is strange at first due to it's shape but I love it now, it's fully adjustable. It's capped at 15bps stock but you can buy a new board from the US which bumps it up to 25bps with adjustable de-bounce.
Very few upgrades for it, but it honestly doesn't need any. Only thing I'd change would be the feedneck, which are impy threaded.
Also, you can't use halos on it as they use too much force and shove the balls past the cam reeds - I use an egg.
If you decide to buy one and are having any problems, give me a pm, I'll probably be able to help you out.