Today's Mustang is not far off the pace of a lot of cars that are waaay more expensive. Factor in a power band that is accessible, handling, a back seat, and a trunk and I put this car up there as an unbeatable performance bargain.
Big question probably is this--can a regular joe drive an "exotic" car much faster than a 5.0 Mustang GT?
As far as today's exotics--based on performance numbers in magazines they are insanely fast in the hands of professionals. Faster than the Mustang GT.
However, if you save your old car magazines (I had every Road & Track and some others all the way back to 1982, then I moved and I had to part with them), anyway, if you look back to say 10 years ago the new 5.0 would be pretty close to "exotic car" territory in a lot of categories (0-60, slalom, skidpad, etc).
Today's 5.0 against exotics of 20 years ago would put it in exotic car territory no problem. Of course you'll find a few (Ferrari F-40 I believe was made 20 years ago and it would beat the mustang).
Drop into the "80s and 400+ hp and 0-60 under 5 seconds is rare. I'm not sure if a C4 ZR1 was under 5sec 0-60, i believe it had something like 385hp?
I haven't had my old magazines for a while now, but that's my recollection. So my rule of thumb is this--exotic cars of say 10-15 years ago watch out! haha (my friend's cousin's Ferrari F355 6-10k maintenance cost $6k-8K for oil change/timing belt change otherwise bye bye warranty).
and to anybody who owns an exotic car--enjoy upkeep and maintenance on it.