I was a quality assurance inspector for the Boeing company for many years until I retired. We didn't use ISO 9000. We had our own system and it works pretty well. Most of the planes they built are still flying. I'm not sure how many AVR manufacturers are using ISO 9000 but it doesn't seem to work very well at times. Look at the problems Onkyo is having with their HDMI boards - and for the past 5 generations of their AVRs.
At any rate AVRs are becoming increasingly more complicated. Everyone seems to want to play music and control their AVR with an ipod/ipad/iphone. It *has* to have internet connections - has to have airplay - pandora - etc etc. When some crappy iphone/android phone app refuses to work right the AVR gets the blame. Never mind that many of the apps are free or $1.99. Then there is the operator errors.
I use an HTPC with a crap-load of music ripped from my CDs to FLAC in my main setup. From there it goes to my integrated amp and stereo setup. In the bedroom I have a Denon 1713 AVR. I plug in a flash drive to play my FLAC files for bedtime music. If it didn't have that plug-in for the flash drive I could improvise and burn a CD/DVD and play it through the Yamaha DVD player. There are ways around a lack of features - you just need to be inventive.
As for costs - AVRs are cheap! I spent $244 shipped for the Denon last month. It'll probably do most of what you are looking to do. I can recommend it without qualms - but you asked about Yamaha and Pioneer. I've owned a few Pioneer receivers - I recently gave my daughter a Pioneer VSX-9900 - a top of the line receiver 10 years ago. Its about as powerful as any AVR I've ever owned - probably on par with the Yamaha RX-V3900 I have in my home theater setup now.
In your price range the Yamaha HTR-7065
would be a great choice IMO. And its one that I recently owned. The 773
is another to look at. The Pioneer 1123
is the newer version of the 1122. These are probably the better choices in the Pioneer lineup IMO. Very good reviews.
Those AVRs all have very tweakable center channel levels - important since you have difficulty with dialog. You simply go into setup and bump the volume on the center up a bit if you like. Thats where the main dialog will be coming from.
In terms of reliability - from what I've read here - and experienced by ownership I think the best to worst is this:
Yamaha - Denon - Marantz - Pioneer - Harman Kardon - and the lowly Onkyo, last due to their lack of a decent HDMI board. I think Denon Marantz and Pioneer are very close in second place. This is of course just my humble opinion. YMMV -- as always. I've owned all of these brands except for Marantz - and I've owned several older receivers from the 60's and 70's. I'm not sure whether I despise Onkyo or Harman Kardon more! I know one thing - I'll take HK customer service over Onkyo's any day!