In the simple, I've had a SR5007 for about two months and haven't a single complaint.
The main feature I found in the SR5007 was a delivered price of $750.00, a full set of pre-outs so as to upgrade to an outboard Amp should I find reason to do so in the future, a good looking front face plate (it was sexy) and it came with all the standard whistles and bells one looks for in a contemporary AVR. In the end, being a Denon/Marantz fanboy, having owned both, I chose the Marantz unit over the Denon unit as doing so makes me feel all warm and fuzzy inside and in the end, I encourage everybody to buy the unit that makes them feel all warm and fuzzy inside.
After the room acoustics were dialed in with Audyssey, MultEQ XT, using unchanged settings, I would characterize the sound quality as clean and what one one would consider neutral. Our SR5007 supplies a 5.2 setup and we're easily able to drive the sound level up to THX reference standards based on a real world, main speaker sensitivity of 86dB, 1w/4m; not a typo.
I haven't found any lab specs on the SR5007 but in checking out specs on other Marantz SR series receivers, if one were to rate the SR5007 for power, rating the receiver at 89w, five channels driven, 1.0% THD, would be a fair rating. With our 5.2 speaker set, using a digital, RadioShack sound meter, we're easily able to reach reference levels of 85-95db, when measuring conversation and normal action scenes. If driving 7.2 channels, one would have trouble reaching reference levels as I would rate the SR5007 at approximately 67w, all seven channels driven, 1% THD.
I haven't done SPL measurements during peak sound levels but considering how easily it reached 85-95dB, I've no doubt, based on past tests done, this receiver can drive the SPL to peak THX SPL requirements of 105dB for our somewhat open room conditions (15X22X12 foot cathedral ceiling); five speaker channels driven.
Our pair of subs are not capable of reaching THX requirements of 115dB. They are capable of 107dB or ~8dB shy of a full subwoofer, THX, reference level, SPL load. That's not the fault of the SR5007.
My recommendation, if not wanting an outboard Amp and wanting to drive seven channels, I'd go with the SR7007 but it would be a bit cheaper and you'd have more headroom by going with a SR5007 and an outboard Amp such as an Emotiva, XPA-5, outboard Amp.
Since buying the SR5007, we have upgraded our center channel to a Klipsch, RC64 II center channel and when we have the money in the budget, we will upgrade our existing pair of subs; more than likely, to a pair of SVS PB12-NSD subs. I fully, if just for ego's sake, expect to add an Emotiva, XPA-5 outboard Amp to assure plenty of amplifier headroom for peak action segment soundtracks. If one were to ask why, In my opinion, replicating the THX, movie theater experience in the home is the sole reason to have a home theater system; stated purpose, stated goal. And yes, I understand that not everybody wants this as a goal and where they live may prevent them from obtaining this goal. Getting kicked out on the street for an ideal is not always a good thing.
Over all, after reading what others have had to say about other AVR's, including the SR6007 and the SR7007, none of the receivers have once turned my head with a sigh of buyer's remorse. In summation, I would say that the SR5007 is a solid buy and if one has their eye on the future, do so with an Emotiva, XPA-5, 5-channel, 200w, outboard Amp in mind.
After two months of use for television programming and cable provided movie content, I have zero negative comments. We haven't run a Blu-ray disk through the AVR yet so I can't comment on a true HD movie audio experience.Here's a HomeTheater review of the Marantz, SR7007.
Draw your own, SR5007, conclusions.
Hope the above helps and if any specific questions, no guarantees, I'll be happy to try and answer them for you.