Wait for Bryce 6,.....which if you believe the hype, will be out soon.  With alleged support for export of models(including booleans) made in B6 to popular formets, HDRI, and hyper-threading , to name a few,  you'll be much better off(IMO). Course, it won't be cheap but there should be an upgrade discount from B5.5 and 5.

"Any club that would have me as a member is probably not worth joining" -Groucho Marx