Pros: Amazing Sound Clarity, Soft & Warm Signature, Punchy & Quality Bass, Solid Build, Good Size
Cons: Comfort issues if you have bigger ears, Pads not too deep, Cable not detachable

I purchased the Denon HP800 which is the probably the same as HP700 and I have to say these are amazing headphones. What convince me to buy them were great reviews I found and especially one article here on Head-Fi where somebody compare them to D7000 and said that these might even sound better for some songs and he gave A/B comparison with lot of details. I am sure you can find it easily.
These are perfect size in my opinion not too big and not too small. Only people with bigger ears might find them not suitable as the pads can sit on your ears then. This is not my case and they are just perfect for my head and ears. In nice package there is only big jack and textile bag which is ok but hard case would be bonus. These are pretty cheap headphones and very underrated. There is no way you get better sound for this price range, got mine for 79 pounds in UK.
When I tried first tracks I was really surprised how good they do sound. Also the isolation is very impressive. I have chance to compare them with my other pair Sennheiser HD25 and HD380. First HD380 are much better for long period as they are extremely comfortable but their built quality is not so good as Denon's. Denon's built quality is fantastic especially like the metal parts where they do extend but also just holding them in my hand feels rock solid. In terms of sound they are very very close to the HD380s. HD380 have a bit better sub-bass and they sound more spacious. It feels like you are in the concert hall where HP800 sounds like sitting in a studio. Somehow I find HP800 a tinny bit clearer / brighter than the HD380. Me personally for watching movies, sitting on computer for long ours I do prefer HD380 mostly because of the comfort and you wont get tired listening to them. But somehow for listening music and working with music, djing, mastering, etc. I prefer HP800. I still cannot believe how good they can sound, very detailed sound... I am actually exploring hidden sounds in songs and tracks.... amazing really.
I do also have HD25, which are amazing, love the fact that they are all easily replaceable and they also sound great. The isolation there is slightly even better. But I dont think they sound better than HP800 (IMO). HD25 sound a bit too much in your face and they are not so detailed than HP800. In terms of bass it's almost impossible how great the bass is in small HD25's cups but again my winner here is HP800. Hard to describe but somehow the bass feels a bit deeper too. Definitely the bigger cups on HP800 helps providing deeper bass. Also HD25 are small but they are sitting on ears and this is not comfortable over maybe couple of hours period. For me they are maybe good for travel or so. 
Just to add that I was testing HP800 straight from the box today and that I used custom made headphone amp but I also use it with the other headphones to compare the sound here.
Few bullet points here:
* looks cool
* built quality
* perfect size (for my head)
* clamping force is just ideal
* sound is amazing, so detailed... wow !
* overall sound very balanced - great for different genres
* best price really you cannot get anything cheaper / better here (IMO)
* it might make you uncomfortable after few hours of using them (might be good idea to try different / bigger pads on them)
* cable is not too long (but at least coiled)
* cable is not detachable
* might not be right for you if you have bigger ears
* note the bass is balanced so if you are basshead it might not be the rigth kit for you
* would be nice to have case for them they just come with textile bag
I am very happy with my decision to purchase Denon HP800. I would love to hear from you guys if anybody else had chance to compare these to the ATH-50 or other studio or djs headphones. I believe there are better headphones than these but I do not believe there is anything better in this price range. Do let me know your experience with these headphones as I like to read other people's opinions. 
I intent to purchase the Denon HP600 as well and use them for travel purposes, please let me know if anybody has them and what do you think. I hope that others find them the same good quality headphones as I do. Especially would love to compare them directly to M50s and MSR7 from Audio Technica. For me personally the Denon brand has the perfect signature in their headphones.
Just recently I found Denon AH-MM400 and probably going to buy these, I am going to post the comparison of these two in next few weeks.
Also note that there are models HP1000 and HP1100, I have not heard these but according my research these do not sound that good and clear.