I've done a comparison between the Image 2b's and M22's. Personally, I slightly preferred the M22's to the 2B's. PSB's have a signature warmth about them that I didn't find appealing to all types of music. I actually thought the 2b's were pretty neutral before I heard the M22's (of course I was coming from some old Bose 301's). I haven't heard the 4T's, but the 5T's at a local shop sounded pretty good. If you already like the PSB Image series sound I'd stick with them as they are a great bang for the buck speaker line.