I found the Kasimdzhanov DVD to be a good complement to Bologan's nimzo DVD, but Kasim's lines are riskier and he is probably abit too optimistic in some places e.g. the b5 gambit in the 4. Qc2 line can be handled with 8. Bg5 (and Nf3/e3) where black isn't as equal as he seems to suggest. The analysis of that 5. Ne2 c5 line seems better but the positions are so unusual that its an acquired taste...

One issue is that there isn't the same coherence in the lines selected as compared to say Sielecki (dark squared strategy), Roiz etc. So Kasimdz would make a good secondary source if you already have other nimzo sources.