My Edition 30 is at 300hp with standard airbox, standard paper filter, standard downpipe and cat back, hell even the spark plugs and coils are standard. Torque was somewhere around 330lbft if I remember right, but obviously that's midrange and not carried to the limiter
The intake is the last thing I will be doing in my series of mods. I'm going intercooler first (MK6 R) and APR downpipe + map tweaks, and then I'll see what the old girl throws at the rollers then.
I hate induction noise. Even if there was a proven 40hp gain (which VW Racing claim for their intake, incidentally), I would still use the factory airbox
I'm not greedy
In all seriousness, there are definitely gains to be had from an intake, providing the extra burnt gases can escape equally fast, so the exhaust should always be done first on a turbo engine. A really good intake will make it feel a bit less strangled at the top end, otherwise you won't feel a lot. It's mostly noise. Most of them blunt the initial responsiveness of the engine at the lower rpms.
The factory box is a complete pain in the backside, don't get me wrong. Extremely picky with the MAF housing and sits right above a roasting hot cat converter....but as said, that natty little engine cover easily flows enough for 300+ shetlands. It's just something to consider if you've done everything else and what every last hp possible.