Many thanks to all for your suggestions.
I actually have FM8.
It is microtunable, but I would still have the problem of trying out different styles with the presets not changing. I would like to go through lots of style changes before I find one I would like, and I don't want to constantly be reloading the VST and preset for every track.
I have been doing some research on the Solton Ketron SD2 that was mentioned earlier, and my understanding from another forum is that it is microtunable. However, I am still exploring how it is implemented, and the manual does not seem to be much help.
Keep the suggestions coming. Both negative and positive, I really appreciate all of the comments.