Wonder how it compares to using Antigrain Geometry. I once had to implement text rendering in a game engine a bunch of years back and I used FreeType to load font glyphs and then fed the geometry data into Antigrain and had it rasterize (FreeType rasterization is meh while AGG is heavenly). Even on very old iPhone hardware I was able to render in the main update loop and not encounter any frame rate hiccups.

Unfortunately AGG 2.5 is now GPL so if you need to stick it into anything closed source you are stuck using 2.4's modified BSD.