igglebert:The key differences between the + and i models are i) the finish is improved with veneering that covers the back of the cabinet, ii) improved tweeter which is smoother and more detailed. I've heard the + and i GB1 and FB1 and for my personal taste I would stick to the i. The FB1 of either taste gives a lot more scale to the music over the GB1. The FB1 is quite an amazing speaker! It never fails to put a smile on my face with it's sheer power and punch. IMO the extra smoothness of the i is a must for the Cyrus kit unless you have a very damped room.
Aye.I can whole heartedly concur with me leaned friend Igg. after having the opportunity to hear both the OB1 & OB1i previously.Particularly with regard to your partnering kit.
The older OB1 could be lively at higher frequencies & a little too forward.Making it sound a bit fatiguing to a couple of my friends who also heard both models.
Whereas the new 'i' version certainly came across as more balanced across the frequency range.The OB1i also goes a touch deeper than previously.Having more authority & coherence at lower frequencies.Due,in no small part,to the refining of their application of transmission-line technology...They handled Massive Attack's 'Mezzanine' & 'Protection' albums with plenty of dexterity on my short-ish demo.
Whichever ones you decide to go for....You could do a lot worse.
EDIT: Perhaps i should have taken my time to read your question properly too...Sos.I haven't heard any of PMC's + versions,i'm afraid.
BABUR.