I just bought my roadster 4 weeks ago. Now that I have driven it for a while, I admit to having a lot of second thoughts about the purchase. Really, almost all of my concerns/reservations are about the price. I have never in my life tied up so much money into a car (my vehicle is a 2010 2.5 sport edition and cost $70k).
I have a constant nagging worry about maintaining my investment, and fear that something bad could happen. Even the most minor of scratches or tiny incidents could greatly impact the resale value of the car and cost a small fortune to fix.
To me it really boils down to just how important is it to you to own an electric car? If it's super important to you, then that will guide your decision. For me, I wasn't so hung up on the idea of having an electric car as much as I was on having a very rare vehicle that presented a unique driving experience.
When you are driving the car between 0-80mph, it's about the most exciting thing on the road. However, if you are cruising on the freeway at 70mph, and want to suddenly 'punch it', there's really just nothing left.
The fact that the car has a top-speed of 125mph and pretty much no acceleration above 70-80mph, doesn't make it seem like a 'real' sports car. Even though I have really no practical use for a car that can go 200mph, the reality is that in that price range, there are a number of vehicles which can approach that level of performance. If all you want is the best possible sports car you can get used for 70k, you would probably just buy a Corvette and call it a day.
One of the things which nags me, is that you can buy a used Lotus Elise for around 25k, which provides a very similar handling and ride as the Roadster. For 25k, you probably would not be so nervous about retaining resale value and less freaked out about something bad happening. For a little bit more, but still less money than a roadster you could own a used Exige or Evora, if owning a convertible isn't that important to you.
For a 70k used convertible car, other vehicles in that price range offer many more creature comforts. The Roadster is very raw, more like owning a hobby/kit car than a nice polished high production vehicle you might see from mainstream vendors.
Even though the performance and handling of the roadster is incredible up to about 80mph, there is almost a sense of guilt that you get all of that with no effort on the part of the driver. Frankly, I miss shifting through the gears trying to extract the perfect acceleration into and out of turns. The incredible acceleration you get out of the Roadster feels almost 'too easy'. It doesn't ask anything of the driver, a child could get the same performance profile as you do driving it. And, while I was never into obscenely loud cars, after 35 years of driving stick shift, naturally aspirated sports cars, I do miss it quite a bit.
With the limited range of the Roadster, lack of creature comforts for such an expensive vehicle, and the fact that it can't really do much of anything above 80mph, it sometimes just doesn't feel like a 'real' sports car to me.
Personally, I wish I had driven both the Roadster and an Elise before I made the purchasing decision. I might have still bought the roadster, but I think it's worth comparing spending 25k vs. 70k pretty seriously.