I haven´t uses tr64 in a while but it´s pretty compatible, however it´s not stable, atleast not on my comp. Stability, good and compatible gfx, doesn´t mather if it´s slow since computers are getting faster and faster, and a compatible core. I would rather have a slow, really compatible core then a really fast one, i.e corn that hardly runs any games, because in a year or so what was considered slow will have changed.
And re game requests any more games working are a plus but if I should get picky I would have to say Rogue Squadron, afaik there is no emu that runs this game. Never games tend to be harder to emulate because of the developers are using new ideas to workaround the existing problems, I don´t know they exact reason for why this game is not emualted but I´m guessing it has something to do with MusyX.
And with the risk of sounding like an idiot, autohandling of Ucodes in your gfx plugin, instead of manual selection. Since I don´t have tr64 installed at time of writing, I haven´t checked if this feat. already exist or if it doesn´t. If it does, forget about it but if it doesn´t please include it, I can´t speak on others behalf but it seems like if I very seldom select the right Ucode.