Don't plan to unload any of them, though sometimes I do wonder why I have so many
What I learned,....well here are a few little items.
Bookshelf systems (as in all-in-one) generally seem to produce muddy bass no matter the room treatments or placement and the speakers tend to color the music,.. a lot.
I have also discovered Kenwood produced a few good HTiB, not great, but for the money the 503 and 505 HTiB could do a respectable job.
Um,... SPL meter and a good set-up disk are well worth the money.
RBH speakers generally have a very good WAF.
Lets see,... Sony DE recievers get really, really HOT when they try to push 4 ohm loads
Monitor Audio Silver 5i made for an awesome nearfield speaker when I hooked them up to an amp and used them for my computer speakers.
Lots of other stuff,.... any specific questions?