Solarfl4re, in your tests, don't leave out the best e-reader for iOS,
Marvin. It's blazingly fast under regular circumstances, so it would be interesting to see it tackle your "accented" book. I use Marvin to read regular Russian books without any problems.
(Stanza is dead, in case you didn't know, and Marvin is very much Stanza's successor, except that it's even better.)