MacType effectively replaces GDI's font renderer (DirectWrite replacement is experimental) with FreeType (used on Linux, not sure about Mac). If you enable ttfautohint ("Auto tuning") instead of bytecode hinting ("Standard tuning"), the fonts may end up with different metrics, and cut off the tops and bottoms of characters. There's a workaround where you can tell MacType to report larger font metrics than GDI would, but this apparently causes rendering errors as well.
Another bug is that MacType makes Sublime Text in GDI font rendering mode chop off the right side of wide CJK characters. Enabling MacType's experimental DirectWrite support makes Sublime Text's DirectWrite text fuzzier, but not chopped off.
Another bug is that MacType makes Sublime Text in GDI font rendering mode chop off the right side of wide CJK characters. Enabling MacType's experimental DirectWrite support makes Sublime Text's DirectWrite text fuzzier, but not chopped off.