I've done loads to it last year. I started off with just a 1st decat and exhaust, had that setup for quite a while. Then I figured it was the time I'd normally have sold up and bought another car, but there was nothing else I wanted so I'd spend what I would have done on another car on upgrades!
Trouble is once you get to a certain point you need loads of things to go any further (to do it properly anyway). I wasn't happy using the standard intercooler at 1.2BAR or more, so I bought the FMIC, 2nd decat and fuel pump. My clutch started slipping, so I had to upgrade that and did the flywheel at the same time. I had it on the dyno at Billing last year which confirmed that the fuelling wasn't enough for more than 1.2BAR. So I brought forward plans to sort it out. I've got an Emanage which currently is adding extra fuel in the mid-range of revs, but I'm at 100% duty cycle on the injectors at high revs. So I now have an Aeromotive adjustable fuel pressure reg to be fitted, which I will use to increase the fuel pressure, then use the Emanage to trim the fueling back everywhere apart from where I need the extra. I've got a wideband to measure the air/fuel ratio so I can set this up correctly.
Still got the standard Jspec 440cc injectors, internals and turbos.
EDIT: That power run was basically running rather lean, which is good for power but not for your cars health! I was keeping it off full boost at the time wiht my right foot! It's probably putting out a bit less now, but it should be back up there when I've sorted my fuelling out properly.