Having a set of speakers from the same manufacturer will make a HUGE difference, particularly the front three if you have to do it in phases. Second, your room desperately needs some sort of acoustic room treatment to control reflections. Third, a second subwoofer will make a big difference in smoothing out room response and giving satisfying bass sound.
I am really liking the XPA 5, it replaced a bryston 9B that i have had for a while and do a whole lot more 2ch listening them 7.1 so it went but i have hooked my mains to this XPA 5 to campare it to my Xindaks and it does a remarkably good job driving them with little effort and great sound stage.
