sensibull, I will try and answer some of your questions first. I found the 80's not a little to bright but a ton to bright. I like you listen to a lot of guitar based music albeit on the harder side. Joe Satrani, Steve Morse etc etc. When these guys get going the brightness was simply to much for me to take. As I like Axiom I wanted to stick with them. Thus I went with the 50's and have not looked back. They sound a lot like the 80's but much less bright. As for the QS8's, I actually have a set of M3's on order to try out as surrounds. I like to listen to multi channel music a lot and the QS8's are a great surround speaker but don't do it for me with music.
You also mentioned that you are thinking of either the 22's or the 60's. I can't really help you there as I have only heard the 22's and they are nice little speaker. Clean is a word that comes to mind. Would I use them as mains, I doubt it but a nice speaker none the less.
With respect to the VP100 versus VP150, as I said before and at the risk of starting a war in these forums, there is squat for difference with the exception of the VP150 is once again and a little brighter and has a little wider soundstage. They both do what they were made to do well and that is pass dialogue.
