I know there are guys that drive them a ton, but for many, a dinky, two seat convertible with no storage isn't going to be driven that much. Unlike a modern car, you have to pick your spots for good driving weather, and traffic has to be considered as well, at least if you want it to be an enjoyable ride. Sitting in backed up traffic in 90 degree temps most definitely is not fun. Today, we just took an early morning drive to a local farmers market we frequent. Our speeds varied up to 70 mph and was about a 35 - 40 mile round trip - a pretty typical drive for us. Drivability has always been fine for us - we've never overheated, and our 1915cc flat four has been more than enough to keep up with modern traffic.
How often Speedsters are driven doesn't seem to be much different than guys that own classic cars. They are lightly driven, but still very much enjoyed by many of their owners. Part of the enjoyment for me is how beautiful a car it is to just look at. There's no shame in that for me - looks play an important role in every aspect of everyday life. There are many classic car guys that pour tons of money into restoring or buying cars and never drive them - they only look at them or work on them. That doesn't bother me either - there are a lot of worse ways to spend your money. At least with the Speedster, you have a beautiful car without spending too much money - bang for the buck is pretty much unmatched in today's car market.
If you love the looks of the car, and don't have high expectations for how often you'll use it, you 'll be happy with your Speedster, no matter how often you drive it. If you start feeling guilty that you're not driving it enough, or you get bored with the looks, you'll probably end up selling it. (and probably should).
Bill