IDK, but I am going off of Zeroto60times.com website.
A $27 Subaru WRX will do 0-60 in sub 5 seconds, so an EV really should be able to do better. You need to make a compelling car in order to convince people that EV's are better. Yes, 0-60 is 6s is plenty fast for most people but you have to "convince" most people that EV's are better. In order to do that, you have to make things "better" than ICE equivalents.
A Impreza WRX STI might do sub 5 seconds (with perfect launch, and good turbo spool before launch) with perfect driving. But that car isn't $27k it is $35k. Is good but not great on the inside. And SUCKS down PREMIUM FUEL. And with a direct cost comparison, you are spending way more on the Subaru when you factor in gas. Plus IMO turbo lag in that car is awful, at least it was for 2012 models. I would take my GTI over one in a second, as I don't need AWD.
Honestly anything under 6 seconds is quick. Unless you have been rolling around in a Model S Performance, or Corvette Z06, or 911 constantly for a year or so will a 5.X 0-60 seem slow. Or you aren't actually pushing the car to what it can do.
But as to the original post I would think Gen III reservations go REALLY quickly. With as much exposure as Tesla is getting at the moment. I am sure there will be thousands of reservations in the first 48 hours. But it really depends on how well Tesla publicizes it. I would expect some sort of party (Sig and Roadster owners invited) with a sign up sheet, much like Bonnie did with her X reservation. Then probably a week(end) long reservation block for all Tesla owners. Then an open to the public reservation. I fully expect to put down a reservation on a Gen III as soon as I am able. I expect a lot of Model S owners will feel the same. I bet there are a thousand reservations before it even really opens to the public.
I think 3-5k within 48 hours of a public press release about reservations being open for Gen III. Assuming pricing is ~$45k (~$37k advertised price) or less before income tax rebates.