I used porscheinspections.com to undertake a PPI check on a 997 at RSJ. Like 911Virgin, RSJ have a great reputation and stand behind a very strong warranty.
The general advice was that I didn't need to have the PPI done because of who I was buying from. That's probably right, so why did I have it done?
I asked Joel at RSJ if he was happy to have Porsche Inspections do a PPI check on the car before I bought it, he said that he was happy to do so, he's worked with them before and added that whilst I should feel confident with their warranty and that it clearly wouldn't be good business for RSJ's business to sell a lemon, he understood that I might want the additional assurance as this was my first venture into 911 ownership.
From my perspective, I didn't want to have to rely on the warranty if anything went wrong and would rather have most issues pre-empted through a thorough PPI check.
So I had the PPI check done by Bob at Porsche Inspections earlier this week. He called me after he had finished the checks and confirmed that the car was a very good car, RSJ were a great dealership to buy from and their warranty was very good. There were a few issues that he picked up on (coolant hoses, a/c condenser, RMS and some exhaust fixings). The call was followed up within a few hours with a comprehensive written report (27 pages). I discussed the findings with Joel at RSJ, who agreed to put all of these issues right before handing the car over to me. Joel said that all of these issues would have been rectified by them before handing the car over anyway, but such a comprehensive report gave me absolute comfort that I would be collecting a car in perfect condition, even though it is 12 years old - this was the real value of the PPI check for me.
I can't vouch for 911 Virgin, but I've only read good things about them.
However, from first hand experience I can thoroughly recommend both Porsche Inspections and RSJ.
I pick up my car this Thursday and can't wait!