Being a driving school instructor/amatuer time trial champion, I have driven both platforms over the past several years. While yes I am a Corvette racer (so I guess that does make me biased), here is my best attempt at an unbiased opinion. I race Corvette's primarly because they are much more cost effective to race in the US than racing imports in general, and they are just as fast or faster especially with mods (which are 1/3rd the price of imports for US).
Porsche 911
- definately higher quality build
- awd models make better street cars, especially in inclement weather
- they are MUCH more expensive
- parts are much more expensive
- they feel good at low speed and around town driving conditions
- with the rear engine I am always able to get on the gas sooner coming out of corners, which keeps them competitive with higher hp cars
- at the limit they take a special talent with a lot of finese or the tail will wag
- you are constantly trying to make up for lack up power by maximizing corner speed and applying throttle as early in the apex as possible (this is your only hope of holding off high powered sports cars).
- awd models are not good at the limit on racetrack conditions, but are better suited to 95% of typical spirited driving or road conditions, they simply push too much in the corners...hence one reason why rwd GT3 with less power is faster
- interior is wonderful
- Car impresses your afluent friends more than a Corvette ever could.
Corvette Z06
- noticeable lower tolerances in terms of build quality and inferior interior
- they sit very low and stiff, with large body overhangs over the front wheel (constantly scraping on driveways)
- they are much more cost effective (cheaper) in terms of bang for the buck and are much cheaper to mod ($10k+ in mods will put you in or past enzo territory).
- the do not feel as good as their german counterpart in low speed driving conditions, they have huge tires, are stiffly sprung, are very wide which makes parking lots and city driving a hassle. Not to mention the shifter is heavier as is the clutch to deal with up to 500ft lbs of torque (can't have your cake and eat it too...not for this price).
- almost perfect 50/50 weight distribution makes it a nice neutral handling car at all speeds. Takes no special talent to drive relatively quickly. A novice could come up to speed quickly (as long as he/she respects the throttle).
- at the limit is where this car wants to live and no where else (Jeremy was not so wrong on Top Gear). You are either driving this car at 9-10/10th's and have found a pure magic wonderland, or if you take this car for a test drive around town at less than 90mph which gives you the wrong impression. This is not a touring sedan or meant to be driven at 45mph throuhg city roads. It is designed to take long sweeping corners at 100+mph with perfect stability. Unfortunately, the test drive should be at the race track, not on the street.
- Handling, braking, and strait line power at the limit are awesome and are in line with cars costing up to $200k, rather than $75k. If I am behind a 911/M3/5 in a corner, once we get on the strait, I am gone... and he can not catch up through the next set of turns and hence I will win.
- rwd in general works at the absolute limit and provides neutral balance (eg GT2/3). You tend to steer with the throttle, and the actual steering wheel is just used to point the car in the general direction. But the car is worthless in snow and handful in heavy rain.
- Steering, gearbox, and handling only show their true wonders and come alive at the limit. It is like having a race car on the street... normal driving conditions would somewhat fustrate you with a heavy gearbox, race clutch, stiff suspension, and lower stance. This is not the purpose of this vehicle (driving at street speeds).
- Torque and power combined with the low weight make this car as tempting as a hot porn star ready to serve your every whim. The pull at 2500rpm in 4th gear is something you need to experience. The power is beyond addictive and brings out the 15 year old in the most mature individuals.
- Will not impress your affliuent friends (especially those who aren't particularly into cars).
In the end I choose Corvette because for the money, they are faster than Porsche's at the race track especially with the right combination of mods. I can maintain the car at a moderate cost. I walk modded GT3's without issue, and are out of their visual site in less than a single lap for almost 1/2 price. For a young mid-level corporate managment guy (basically succesful, but still working man), I'd prefer to spend my hard earned money on the Vette and get the experience of a lifetime (I want the adreline rush of an unholy beast, rather than sitting at the wine festival trying to impress my friends with my expensive achievement trophy). Maybe when I am 50+, I will retire into a nice 911 Carrera and attend the wine festival, but at this point I know I would look back at my 30-40's and say (I should have bought the vette and rode the lightning while I had the chance.) You are young once. To pass an F430 Scuderia on a race track is something one should experience and should not be just for the inherently wealthy if possible. The wine and cheese would only melt and stain your racing suit.
Now it's up to you to decide...would the helmet only mess up your hair, or are you ready to get drunk on adrenaline?