I'm going to go ahead and give my humble opinion to my own question because I couldn't find much information during my search while I was on my journey looking for an upgrade and now that I have my upgrade maybe this will help someone during their search.
I ended up picking up the Denon 3312CI yesterday, I would have opted for the Pioneer-SC61 but they were out of stock, I hadn't heard either before my purchase. My old receiver was a Yamaha 371, the specs are 100w x 5. Actual power when 5 channels driven is ~32 watts!
No auto setup to speak of, had to manually set everything. I used no metering tools or software only a tape measure and many many manual adjustments made by pure ear preference.
Premier Acoustic PA-150 subwoofer (15" woofer, 250w rms 1000w peak)
Polk CS2 Center
Polk Monitor 60 Left/Right
Premier Acoustic PA-6S surrounds L/R
~7000 cubic feet
720 square feet
30 width x 24 length x 10 height
This includes living room (Home Theater) open to kitchen and dining room. There is a 4 foot wall dividing the 30 foot width at about 16 feet. The home theater is in the front 10 foot of that 24 foot length, at about 13 feet the kitchen starts. I don't have the most ideal room for home theater.
Before my receiver upgrade:
I like my setup, I've heard better but 99% of my family friends and neighbors had not (I have 1 neighbor who has a really nasty setup room treatments and all that jazz... drool). When we watch a blu ray we always play it loud, since I had no meters and my system had no auto calibration we would turn the volume up to a level we thought was, well, reference level. On my Yamaha system what we thought was reference level was around -5 to -10 db. My fronts were manually level reduced by -5.5db and I had my surround at +3db (this is after all my tweaking and testing. My center I had at -4db. My sub I had at -6db. At reference level my system was lound, pounding and need a say sounded pretty darn good, however, I could tell that there seemed to be a richness that was missing. A non enthusiast would be proud of it, heck I was proud of it, but I got the bug and had to upgrade.
After the upgrade, Denon 3312CI:
Setup was easy, very easy, albeit I have been reading about Audyssey setup for some time now on here and the Audyssey forums. I measured 8 positions. My family was home, I had them in the back room, quiet as mice. I was rushed to make it through the 8 positions so I didn't check my sub level until after all 8 were done, I thought I had my sub volume at a level that would not result in a -12 db but I was wrong, after calibration I checked and sub was set to -12db. Oh well, I didn't have time to do it again so I manually lowered the sub volume. It set my 2 fronts to Large with full range crossover, I changed them to small and 80hz. It set my center to 40hz, interesting, I changed it to 80hz, it set my surrounds at 90hz, I left them where they were.
To my surprise my front and center levels were pretty close to what I had manually tuned them when using the Yamaha. The left was -7.5db and the right was -7db, the center was -8db, I left all the levels where Audyssey set them. The surrounds were set to -3.5db, left them as well. All the speaker distances were accurate and much more accurate than what I could set them in the Yamaha which was limited to 6" increments, so I was glad about that. LFE was set at 120hz.
After setup I popped in Transformers: Dark of the moon. I cranked it up to 0db. I watched from the Paramount Pictures intro and the beginning story where Optimus is talking and the autobots are trying to escape in the ship. I watched the first cut with Shockwave as well as the car chase scene and then the city scene with the guys jumping out of the plain. Right from the get go, the Paramount Pictures part had a richness that was not there before. The loudness was the same (as far as perceived loudness). All the other scenes though were shockingly "dense" as well as "spacious" and the synchronization of the sounds from the speakers when sounds pan across the stage were perfect. In my old setup I could sort of hear where timing/delay and or tonal changes from pans could cross speaker plains, of course I was listening for this, with this setup, no, it's awesome. I didn't get to test very long at these volume levels, but what I did hear was great.
With that said, to answer my own question with my own opinion, most definitely you will hear a great difference in sound quality, presence, denseness, richness, spaciousness going from a HTiB receiver to a quality receiver. Perceived loudness is about the same, which I guess I wasn't expecting but then after thinking about it it makes sense. I already had the old receiver cranked to what we thought was reference level which is very loud, too loud for some people, why would I watch a movie even louder, then obviously there is the whole you need 10x the power to double perceived loudness etc. So even though I thought I wanted or needed louder, that wasn't the case. I wanted and what I got was a more detailed and full sound at the same perceived loudness. At those levels on the old one I know realized there was definitely distortion and a far more "hollow" sound from all speakers.
Without dynamic EQ:
At volumes below reference level, like say -25 to -40db to my surprise there was almost no difference in the sound as far as the details and clarity not being there. As I went a bit higher and pushed the receiver more and approached reference level there was a definite quality of sound increase. The fact that at the lower levels it really didn't sound any better than my Yamaha, except for spaciousness and accurate pan sounds, immediately crushed my honeymoon experience. Having said that, that also makes sense and once I could accept it I was happy again.
With Dynamic EQ:
Below reference with Dynamic EQ I was really impressed, really impressed. I try to watch what I can loud, but it's not always feasable, with my old receiver I would on the fly adjust the levels of my surrounds when I knew we were in for a movie or something that was going to be at a medium volume, even then the sound wasn't quite right. Dynamic EQ really sticks out here, without adjustments to any speaker EQing or Levels it does so for me automatically and you can really hear it. It will never be the same as reference level but it is far more satisfying, in my opinion, than what I previously had preserving that spacial and surround effect. Sounds that would be completely lost are now back in there, thuds and what not that would only thud @ reference now have the appearance of a thud for that relative volume.
I need to go back and calibrate my system again so I have a properly setup subwoofer, however, I am very satisfied with my purchase. Going from junk to crunk is audible, very much so and I definitely approve of that message.