i have a austrian trysis 260 OS and string it up with kirshbaum proline evo and 58/56. imo a crisper syn gut like OGSM strung around 62 or a crisper/older generation poly strung in the high 50s work really well with the bumblebee. not sure about the other versions though as it's the only OS radical ive owned. crushes the ball!
Used the Bumblebee with 60# Polystar back in 2003. Awesome