With the latest SVN tree, there should be a number of considerable N64 optimizations, including a muchly-improved RSP DRC and more RDP flattening. The following caveats should be noted:

1) There is an as-yet unknown bug affecting texel lookups for certain texture types, as exhibited in Tetrisphere.
2) I have temporarily disabled vi_filter16 and divot_filter16, because there are a few fiddly things about them I don't trust. This has given a temporary speed boost, but expect a slight drop in performance once they come back online.