Ok so I gave this a go yesterday whilst at work...

Boost comes on very hard , sweet fark all until 3 g then bam (snap neck)...
The poor lil td04 wound out very quickly.

I was just around the corner from home and gave it a bit, hit boost then bam engine light came on lost all boost, and putted home.

The vacuum line between the restrictor pill and the waste gate actuator was split (due to temporary fix when I was installing a top mount last week).
So i fixed the vacuum line correctly, hooked it all back up and still my car had engine light on and running like shit, so i took the grub out and engine light disappeared straight away.

I am temped to give this a go again but probably should install a boost gauge first.

Be interesting to see how other people go with this.