I assume you mean 207-215 for your water temps.
also, I have heard that you don't want to go too high in intake temps (I haven't been brave enough to test that one) I have heard that above 180 isn't good. there again, I don't have personal experience.
mine isn't adjustable (at least not on the fly) but here are some pics. it seems to be working pretty good. I have seen temps of 179 and that was on the hottest days so far this year. most of the time it is between 130 and 150
http://www.gassavers.org/garage/view/1372
I know, a link and not actual pics. sorry, I'm lazy.