Caanga you really idolise the work of Porsche engineers and I don't blame you for that. BUT;

You need to remember that P like any manufacturer has to comply with many regulations and cater to the needs of a wide range of markets, roads, climate conditions and ... driver skills. 

Regarding the suspension, if you check what most GT2/ GT3 etc track users were doing for the last 4 years (myself included) was to effectively take components from P motorsport or other AM suppliers and improve the suspension of all the GT models. Now if you also ask around you ll see that it is documented that you can actually improve handling (and track times) considerably even on a GT2 or GT3. Now come 2010 Porsche decided to actually include some of these parts on a new model called GT2RS! The trick of course is to optimise handling without completely killing everyday driving ability. I personally experimented for over 2 years, changed back and forth components until i found the perfect compromise for me between handling and NVH. And it is considerably faster that any GT model included the GT2RS on a track according to my tuner that test drove it back to back with (their own) race prepared GT2s. 

Regarding the engine I have gone the same path with Toby and I discovered all of the things that he is trying to explain first hand. ie. by spending the $$$ to get it right to nth time lol!

You can't get more than around 650hp-670hp with proper thermal efficiency to accelerate hard (i.e. beyond 60-130 runs blah blah) if you don't substantially modify the engine. The US tuners can provide packages with higher quoted power figures but trust me they fall off a cliff beyond 200-220 km/hr where the limitations of the VTGs etc start to show. Again, we can all read as many magazines as we want but unless you try (and fail) yourself it is difficult to understand where the truth lies. 

For the record this is a video of how 740hp 950NM (european hp) accelerates up to 300kms+.

http://www.youtube.com/watch?v=msLPtGaKoHA

This engine has almost all possible improvements (engine blueprint, cams, ported heads, flaps etc etc) while maintaining full VTG factory setup to make that power until such high speeds while maintaining near stock drivability (or better actually). And it cost $$$ and >100 hrs on dyne to tune. And still I believe on race conditions it would lose 50-80hp after 10 laps. Do you really think US tuners can do better than that with just external mods? Me not think so