Both keyboardists are fine players. I think that style and fun factor points go to Vadim, his extended keyboard solos with the videogame samples and playing with his nose and playing popular tunes within his solos and such are great, and his blood-spattered keytar really fucking kicks ass. Good performers.
However, I do feel that in general playing skill Jamma Warman has him beat. I think his parts are more complex and even though his demeanor on stage is nothing more than statuesque, his playing and soloing are top-notch and it is a joy to watch him play his tilted keyboard. Overall I feel that Janne's keyboard parts are also better-written and more tasteful that Vadim's as well, though both bands are very much over-the-top. I think that Janna and Jaska (The drummer) are easily the most talented band members from COB.
Obviously there are better performers out there. Staropoli from Rhapsody (As previously stated) is miles ahead of those two, and he is also a brilliant composer in addition to an extremely strong performer. He is easily a favorite keyboardist of mine. I'd also like to mention that the Keys play for Sonata Arctica is very good, though his pitch-bending does get stupid and overbearing at times, in a live setting. But his playing rules and he does a great job of using keyboard in the band in the style of a guitarist.
