These HPFP problems and stories always made me nervous when I had my 09 535xi sedan, however I never experienced any troubles related to the pump or injectors. The car was not flawless though having experienced many electrical issues and even a blown power steering pump hose just in the first 3 months of ownership.
One of the reasons that I got the SHO was because of the direct injection, twin turbo designed engines that it shared with my BMW. And for the most part I'm very satisfied with my SHO, however my BMW was FAR more fuel efficient than the SHO. I find the EcoBoost moniker to be complete bull-****
In fact the fuel economy on my SHO is so dismal that I've found that my old 2005 Chrysler 300C with a 5.7L V8 got better mileage numbers.
If I had bought this car primarily for the fuel economy I would be really mad about this, but it was the performance and nostalgia of the original model that made me get it and for the most part i am happy with it. Being an IT professional I think that the technology really attracted me to this SHO as well and it doesn't disappoint!