I've got no numbers or figures for you (sorry 'bout that) but I've had my 200tdi taken to allisport and had a full width intercooler fitted and its fantastic. I'v been driving like a maniac around town and I even overtook someone on a hill!!
Ok, so I'll get bored of the new found acceleration and the sooner the better as my fuel consumption has taken a hit from my Nigel Mansell like driving, but it was the best £400 I have ever spent (apart from my stag do, but thats another story.......).
The guys at allisport are superb and if you dropped them a quick email I'm sure they would give you a hint at what they set the boost at.