As far as replacing your regular in all situations, I know we all realize that this cant be done yet until supercharger are at most gas stations. Cross country trips is out. But I am in Albany. Based on the fact that 65 to 70 is the norm on most highways, I think that has to be expected on even day trips. So if a 300 mile range is really rated at 265 but based on highway speeds it drops to 80% of that (something I heard), I cant really drive to see a yankee game or go to Boston for the day. a 2.5 hours trip without arranging for an overnight stay. Even then my charge will will most likely be someones 110volt outlet. With the smaller battery pack I am not sure I can even get there.
If you are plugging in overnight at your house even 180 miles is probably more than enough for almost everyone. What people need to know for now is, assuming all or most highway mileage, how far can you go round trip on a daytrip and make it home. And if you need to go more than that, what is your charge time at a regular outlet, which is all you are likely to find without careful planning, to extend your range.