Some people like myself have been skeptical about the glowing reviews of this Mixer. Allot of people write enthusiastic reviews hours after buying a product but I've had a week to really test just about everything on this unit. I can now say that it is as good as others have hyped it to be. Lately I have done allot of reviews on Amazon. Some 5 Star reviews I've given were generous but this Mixer is an easy 5 stars once you find out how to work around the quirks that it has. My reasons for the rating are listed below:1) If your using this for a PC mixer like me, the Sound Card built into this is worth at least $200 right off the bat. I have a Peachtree Audio DAC that is worth around $300-$400 and I haven't been able to tell the difference between the two. A smaller Yamaha USB mixer that I tested before this had badly distorted sound at medium to high volumes. Recording quality was good but it just sounded bad when using it as your primary audio device. The ZED has sound quality that will satisfy all but the most anal audiophiles. It's so good and convenient that I don't even bother switching back to the main DAC. I also love L/R LED lights on the unit as it lets you know if your close to clipping the audio.2) This has just about everything you'll ever need for everyday practical use, unless your a serious DJ that does allot of live music mixing and need sliders for more control over the Equalizer. 4 Mic Inputs and XLR Stereo outputs for Studio Monitors. It has USB, RCAs, Several 1/4 Jacks, Aux/FX outputs, Line Inputs, Guitar Inputs, (it doesn't have MIDI Inputs but you can get an adapter cable that will work), EQs for every channel, Fading, Panning, 2 Stereo channels that can be turned into 4 and a great headphone Amp. Almost everything needed to power a small band.3) It costs $250. It's only slightly more than other leading brands. Yet it has better build quality, more features than most others in the same price range, better sound and headphone amp than others I've tested. It is practically dead silent compared to others I've tested or heard from many other reviewers. It's nearly flawless with only a couple of issues which you knew had to exist since nothing is perfect..The only glaring one I can find is that there is no real Mute buttons. Except for the Record Bus button which essentially mutes your Main Speakers if you have them plugged into the Record Out jacks so you can listen to headphones. Other than that you need to turn down the dials if you want to Mute your Microphone or any other individual channel for example. Another one is that all the Headphone 'Listen' and 'Phones Select' buttons are Mono. So you can't use the mixer controls to change the treble/bass/balance when listening to Stereo music through headphones. Unless... you get crafty. You can use all the controls while listening to Stereo if you connect 1/4" TS cables to the FX and AUX out Jacks and plug them into the Stereo1 Inputs. Then connecting the Record Out Jacks to your Amp or Speakers and it will connect you to the Stereo2 Inputs. This magically gives you full access to control the audio of your headphones in Stereo!Another problem was that it didn't seem like I could use my Stereo Mic since all the Mic channels are technically Mono. However you can work around this as well, as others pointed out. Simply turn the Pan Dials for one of the Mono Left channels fully counter-clockwise and the Pan knob of a neighboring Mono Right channel fully clockwise and you get Stereo separation that easy. So really this mixer can technically have 4 Stereo channels along with 4 Mono.The only noticeable line-noise that I noticed from this unit was when you are listening to headphones or speakers turned up loud and have Microphones plugged in BUT don't have Phantom Power enabled. You will pickup feedback from your computer and/or electric feilds close to the mixer. As soon as you turn on Phantom Power the feedback is gone. This won't be a problem most of the time since you usually have Phantom Power on when a Mic is plugged in. But for those that like to leave the Mics plugged in, this could be a minor issue. So if you are listening to headphones or speakers and hear some odd feedback, simply turn on Phantom Power or pull out your Mic cables and your clear. Just make sure Phantom Power is NOT actually on first.The only other complaint some may have is that this does not have 24-Bit sound. After much research on the topic I've found that the difference in sound quality if ANY compared to 16-Bit is very small unless you have superhuman hearing. The great part is that allot of people have bought into the marketing of the 24-Bit/192 Khz hype and allows people to get incredible deals on older technology because of the lower demand.So why did I waste my time writing this long review and helping people so they don't have to go through all the troubleshooting that I did? Well this Mixer in my opinion is worth at least $400-$500 considering that it replaces my sound system and does everything almost perfectly. Your Welcome.UPDATE: I'm normally careful not to exaggerate in my reviews but I'm going to have to backtrack on my claim that I couldn't tell a difference in sound between this and my more expensive DAC. When switching between the ZED and my other DAC you can tell the Peachtree is sharper and more neutral. It's not a MAJOR difference but it is significant. The difference is more apparent through headphones. I just didn't spend enough time critically listening. Guess I'm a hippocrit and fit into the anal audiophile category I was talking about but I can admit when I'm wrong. So I've concluded that the Audio from the USB of the ZED is good but not great. It's still sounds great in comparison to the other Mixers in this price range. Recording quality is much more important than playback anyway and it does a fantastic job at that. It's features are invaluable for recording and producing music. I've had no problems with it at all to this point and it's still a great value for the money.I found a solution to the USB sound issue as well by not using the ZED USB connection. Instead connecting USB from my PC to a small external DAC which outputs the sound through RCA cable to the ZED Stereo In. Then another RCA cable from Record Out to the RCA Inputs of my Amplifier. Good improvement in sound quality but this introduced noticeable interference noise at about 1/2 gain and gets louder as the volume is turned up. I found out this is due to a Ground Loop and I was able to fix it with a USB Isolator. Everything is great! I just need to switch back to the USB of the ZED if I want to record.