Feature:
The colour display really lets you know whats going on - no more having to guess exactly which label a rotary knob is pointing at - or getting glared out by a bright LED next to a faint label in a dark environment. The in-built sampler is neat too, and the effects are not only BPM linked but also rise/fall effects such as flanger, dont start their rise/fall cycle until YOU want them too - unlike some units where the rise/fall cycle is simply running in the background all the time.

Quality:
Solid, robust all metal contstruction - no loose elements, no damage evident - very well protected by packaging.

Value:
The price of this mixer isnt cheap, but it is in-line with the price of other 4 channel mixers from well known manufacturers. This mixer however, offers new circuitry, and far advance design features and ease of use.

Desirability:
Nothing else quite like this baby.

Sound:
The Menu presets allow me to adjust the centre frequencies of the EQ controls on the music channels enabling me to tailor the mixer to my own sound system - eg: centre the bass eq to my woofers most efficient freq.range. Also, the Denon even allows me to select an EQ for my headphones during cueing eg: Bass Boost, High and low boost, etc. I replaced my cobwebby Pioneer DJM-600 with this unit, and its outperformed it easily in terms of sound clarity and ease of use.

Support:
The unit seems to have taken on-board comments made by DJs on the Denon forum. Also the USB port on the back of the unit allows new software updates to be added to the machine - I've just downloaded and installed the latest software update from the Denon website- it was free and took about 3 minutes to install - more updates promised.

Overall:
Thanks to the USB update port - I see me and my DN-X1500 being partners for at least 5+ years if not alot longer.

Feature:
The input matrix is great. You can have one input play on all 4 channels if you wish, eq them differently, add effects to one, assign them to the crossfader however you like. The mixer is so adaptable. The effects sound great and are easy to use. The presets are remarkable. You can change the headphone eq settings, changes to eq ranges of the highs, mids, and lows knobs. You can add new effects. The screen is very helpful too. The USB plug in has been invaluable in adding desired upgrades.

Quality:
This one's solid as a rock. The quality stands out as soon as you open the box.

Value:
This blows the Pioneer 600 out of the water. It should be twice as much.

Desirability:
Play with it for 30 minutes and you will rob a convenience store to buy one.

Sound:
The sound is incredible, crystal clear, with masses of headroom.

Support:
I needed advice from Support to get the software update. They were helpful and quick to respond.

Overall:
For sound quality, build quality, and variety of features the mixer is a must have for the "dj mixer under $1500" league.