out of those ones you mention my choice would be the pioneer.
another i would consider is whatever harmon kardon is in your price range.
to me either one of those manufacturers would be a toss up.
now one other thing many people will tell you is that both the pioneer and harmon kardon are on the warm side which can be really nice for bright to moderite sounding speakers.but might a little to warm for speakers that are allready warm.
so basically for a speaker like a jbl or klipsch that can have some excessive highs those recievers can tame them nicely.but if you have a rather dull sounding speaker you would be better off with something else.
I am considering the Onkyo HT S770 surround sound speakers. I don't know if these are what is considered bright. I only listened to them in the store with a Onkyo (not the one I am considering) receiver providing the sound. Would the Pioneer still be a better choice over the Onkyo?
i don't know those specific models and don't want to advise you to get them or not.
but from the onkyo speakers i have checked out/ listened to yes they were bright and very cheaply made.
if your looking for speaker choices i would post a question in the speaker forum and hopefully some of the guys that are more knowllagable than myself could help you.
their are a few guys on these forums that really know speakers. like hawk or elitefan or gergory i'm sure their are more and i don't want to affend anyone but i'm drawing a blank right now for names.
On the HK's, they seem to be light on the power in the price range ($450) I am looking at. The only ones I see in that range are the AVR 330 and the DPR 1001. Are these going to perform better than the Pioneer?