As with most audiophiles- converted to Videophiles/HT meisters, you missed the obvious. Yamaha!
I walked down the same road for nearly 3 months seeking the holy grail of AV receivers in the under $2k realm. I concluded the same as you Marantz 8001, Pioneer 84TXi AND, Yamaha RS-V2700! I listened to them all and IMMEDIATELY knocked the Pioneer out as being thin sounding and having limited soundstaging and depth, when compared against the Marantz. (Pioneer since the 1976 Sx-1250 receiver and its brethren, has a history of being powerful but thin sounding from the lower mids down, with limited soundstage designed for JBL or similar speakers with bloated bass response).
Further listening revealed the Marantz very good sounding, powerful, VG depth and staging, if a tad midrange bloat (shades of Denon) but with limited video upscaling features for the older formats (VHS, Laser disk, DVD). Almost a winner UNTIL the info about LFE issues, older 1.1 HDMI logic and severe issues about the uncooperative Customer Service failure to provide consumer availability and timeliness of a new issue date. OOOooohhh, I forgot to add COST! Try as I might, I couldn't get this delivered for under $1400-$1500 with all of my contacts!
IMHO, not worth the wait nor the chance that the technical issues are NOT resolved or in our lifetimes. (Not at this price!)
I decided on the Yamaha RS-V2700.
HDMI 1.2a, upscaling via composite, component, HDMI to HDMI out, or to component out.
4 in-1out HDMI, 3 zones of operations, NO LFE or firmware issues(at this time) and the always outstanding Yamaha Service(2yrs). Added to this, the Yamaha sonics, which has always been quite good. Solid construction, interchangeable power cord. One caveat has to be brought up: This unit runs warm to to very warm and requires good ventilation (So whats new here? Don't all good fanless units?) just be aware of that so you have no surprises from the A/V ignorant which surrounds us!
Sonically compared to the Marantz, the bottom ends are comparable (if not slightly faster due to the 36,000ufd of caps), mids equal, highs based on which cabling you use, it could to either unit. Using audio quality Interconnects to judge: With Kimber Hero, the Marantz wins, with Straightwire Serenade, the Yamaha wins.
Using the strict HDMI feed, the differences are not as readily detectable.
From a speaker cable perspective, its a toss up- using Kimber 8TC or Straightwire Serenade. The Serenade (though much more $$$)is a smoother cable overall when used in a traditional AUDIO system.
As for price, I bought mine for $1050.00 w/tax delivered and haven't looked back. It will take me months to figure out all of the possibilities. Right now its the engine for :
Pioneer Elite Pro 1140HD
Scientific Atlanta 8300HD STB /DVR
Oppo 981 DVD
Pioneer Elite Laser Disk
Sony SVHS recorder player
Paradigm Mini Monitors v5 (front)
Paradigm CC290 v5(center)
Paradigm Atoms v5 (rear)
SNELL Basis 300 Subwoofer
HDMI cables -6ft Monoprice.com -24g- # 2219
Audio Quest Type 4
I hope this litany helped you in some way.