I've recently received a kind email from Erwin Denissen at High-Logic filling me in on a few details of the latest release of MainType. I think he contacted me because I've been rather vocal on the topic of font managment for Windows (27616, 30644, etc.), and have, for the most part, been holding up Proxima's FontExpert as the best of the bunch (IMHO).
After Erwin's email and a few messages back and forth, I have to say MainType is quite impressive. The interface, easily customizable, is similar to FontExpert and includes the panels you'd expect. The preview-text panel is nice in that you can simply type right in it: no saving text files or jumping to Options windows to create sample strings [although the preview doesn't pop in OT featured switches]. There's also a handy zoom panel, where clicking on a glyph in the Character pane displays an enlarged sample of that glyph in its own pane.
The Character map panel itself lists each Unicode grouping that is mapped in the font, providing access to what you're looking for in a nicely organized fashion. Aside from a small bug that Erwin has now fixed, the only thing missing is an option in the Character panel to view glyphs which are missing Unicode points (for example, Fedra Serif B Pro doesn't have it's small caps mapped, which means you can't see them in MainType at the moment); this is, of course, a weakness in such a font itself, but Erwin has mentioned he'll look into making these glyphs visible too.
Auto-activation for InDesign/Quark is absent, but after raising a stink about this a while ago I've come to realize I don't really need it anyway. Handy, sure, but the implementation of the plug-in in FontExpert was clumsy (slow) and I ended up turning it off. Besides, I'm a freelancer, so if I can't keep track of my own projects I should probably take a holiday, not bitch about the fact that my software is lazy.
I should also mention that my main irritation with FontExpert was a real lag in start-up, and the fact that the app didn't sit in the system tray made this worse because every start was a fresh (slow) start. MainType is much quicker on the draw, and you can either keep it active in the tray or shut it down to free up some processing juice.
For what it's worth, I'd strongly suggest those still hunting for the right manager for Windows to take a look: http://www.high-logic.com/maintype.html