Along with everyone else, my ONLY reservation would be the maintenance cost of ownership on the 911's. I'd LOVE to own one, but if used, I'd go no more than a few years (which places them WELL above the price of a Z).
A friend of mine is a Porsche fanatic (uses a 1973 [I believe] as a DD), and takes his car to a local "mom & pop" place that eases the fix-it and maintenance costs. I tell you what: it's almost a 40 year old car, and it's always an experience to ride in the passenger seat. I'd get REALLY excited, but the smell of fuel usually turns me off.
He loves it though, and besides - it's a 911.