Your audiophile friend is justified in wanting you to hear the speakers before you buy. Rarely does anyone buy a car without ever test driving or even going to see it on the lot, so it stands to reason that same cautious point of view should be taken towards your electronics purchases as well.
That being said, many people on these forums will gladly fill you in on their fine Axiom speakers but some others will also be more than happy to tell you about what they don't like. Those negative qualities may or may not be things that will concern you, but you may never know until you do an audition of the speakers.
Are they going to be an upgrade from your Infinity? That is really a question that only you can answer. Just offhand i have not heard those Infinity speakers but perhaps someone else on the forums who has heard them may be able to give you a more direct comparison.
If however you are looking for speakers with more detail, i have no doubt that the Axioms will provide that for you in droves (assuming your source equipment is also relatively decent).
As for comparing the Bostons to the Axioms, the sound similarities will come down to what an individual hears and prefers, but I would not make the assumption that the speakers will sound similar because they use similar materials for their drivers. My old Technics speakers also use a 1" titanium tweeter and it doesn't sound half as detailed as the one in my M60s.
In regards to what models to choose, i would not be overly concerned about your 5.5 foot limit on spacing. Perhaps 5 or less would start to become a little more of a concern. At the present time my M60s are barely 6 feet apart. Setting up a proper triangle from the speakers to the listening spot compared to the surrounding walls is really the key.
I mentioned in a forum review not long ago that i felt the M60s were not really meant for a smallish room but after some positioning and 'toeing', i managed to create a very decent soundstage for my listening area. I have to add though that the VP150 and QS8s i bought are helping a heckuva alot in this regard.
In comparing the M22s to the M60, i suggest you do a quick search for a review i posted recently in which i had the opportunity to listen to both while deciding on which i wanted to buy. I know there were some other reviews you may also want to read on the M60 and M50 models (again on these forums not long ago).
I hope this will help you somewhat in making your decisions.
