I've had my ETRSi for about 20 years, and would answer the question now the same way if it was asked 20 years ago. Those people who want quality photographs will use medium format over 35mm, the negative/transparancy is about twice the size of 35mm. 645s are smaller, lighter and have so much more avaliable in terms of viewfinders winders and lenses at a more afordable price than larger formats. Forget fast action sports with these things if you take one to a tennis match you would probably be chucked out cos the mirror slap will drown out the players grunts.
Target market now? The same, film users who want great quality negatives/transarancies.
They are fun to use, so have fun.
David