The FB1i's midrange will be better due to firstly having a dedicated midrange driver, and also the nature of the driver will outperform most cone based midrange drivers. Your choice may be governed by their compatibility with the room - the FB1i will produce a much better and stronger lower end.
PMC's are my favourite sub - £2,000 speakers (the ones I've heard). I can't comment on the FB1's (a few of the other members really rate them) but the GB1's have a fabulous all round game. The GB's bristle with detail and have a great midrange and bass for the money.
What is your current system? My appraisal is based on my sub-£1,000 per component set-up [way below, in fact]. Also bare in mind the FB1's are considerably bigger, so they should scale easier.
FrankHarveyHiFi:The FB1i's midrange will be better due to firstly having a dedicated midrange driver, and also the nature of the driver will outperform most cone based midrange drivers. Your choice may be governed by their compatibility with the room - the FB1i will produce a much better and stronger lower end.
You're referring to the OB1i not the FB1i.