here's a couple links for the pitts bipe review
http://www.rcuniverse.com/magazine/a...article_id=981
http://www.rcuniverse.com/magazine/a...article_id=924
both of these have good reviews. greatplanes just released the revolver bipe, no review on that one yet but it looks good
http://www3.towerhobbies.com/cgi-bin...?&I=LXTEU9&P=0
i fly both the electristar and the t-28. the t-28 is much more airobatic then the electristar.