I have found Philipp very easy to work with. If you are dissatisfied with his rendering of the Cyrillic glyphs, why not work with him to improve them, instead of complaining? Surely you don't expect a German to be expert in the esthetics of Cyrillic type?
This does call attention to what seems like a deficiency in our font handling: we shouldn't expect a single font to provide the best rendering for all languages. We need a way to mix and match character ranges from multiple fonts, for its default renderings. Maybe OpenType already has this, and we just need code that actually supports OpenType properly.
A side note: my satisfaction with Linux Libertine is as displayed using subpixel rendering on an LCD screen. Be sure to turn on this option, and anti-aliasing using it.