Let me start by saying that several months ago after they first came out I bought the PTM-33 Four Channel IEMs unit For my band.We are a techie band and are continually upgrading our equipment and technology.For purposes of this review I was using the Soundcraft UI 24 digital soundboard, Sennheiser XS wireless microphones, Multiple SM-58 microphones, and both wired and wireless bass and guitar connections.Also at the same time the four channel PTM-10 Wireless IEM system.We are a five piece band and previously we upgraded to the PTM–133 wireless IEMs from wired IEMs (you can see part of it in the picture) . As for us it is very important for each band member to have their own individual mix which they can adjust on the fly as needed not sharing a single “house” mix.I am the drummer and therefore stationary when I play LOL and so is the keyboardist so a wired connection was not a problem.However after reading the reviews and wanting to round out all wireless IEM’s for all band members, and have to deal with one less wire, I decided to buy this system so we are entirely wireless for IEMs.It is definitely a step up in that it’s stereo is a very nice addition.I tested it rehearsing with the band with multiple wireless microphones and four other wireless IEM units ( PTM-33) and Wireless Instrument connections and we had zero issues with connectivity, latency, sound quality, or drop out due to issues in the wireless spectrum.I was actually quite surprised as the environment we practice and also has quite a strong Internet Wi-Fi ( access point on ceiling above) and the soundboard which is the Soundcraft UI 24 has its own onboard Wi-Fi as well.We experienced no issues this was a very big positive.There are a ton more channels to choose from on this unit than the PTM-33 but I found I really didn’t need to mess with that much as I had a solid signal from the get-go.With regards to stereo versus mono I tested them both.Previously when we were wired we listened to a mono mix as the instruments are largely mono and we divide the keys and electronic drums Into two channels.We were simply panning everything in the middle to get an even mono mix with the other instruments divided however there was not much of a divide. Additionally with the arrays we play live with we find even splitting out vocals and panning the instruments gives us a different effect and can sometimes have phase shifting etc.That’s a little too much detail lol (But trying to help illustrate our setup)I tested it both with quarter inch TRS and XLR inputsAnd both in mono and stereo and could not discern a difference in cable type on either.Don’t get me wrong the stereo is awesome! You just need to be set up for it and used to it. My guess is unless you were actively touring you were probably working more in a mono world even everybody having their own mix is a bit sophisticated as well. However if you’re looking at a stereo type unit then you know what it is and what it brings to the sound.I’ve been working in mono world for a long time so stereo it was a very pleasant change but, would stress that people need to understand what getting a proper feed and stereo really means on the input. Stereo is awesome though :)The PTM-10 It is chock-full of features that the PTM–33 does not have. The individual balance is really cool you don’t have to do it on your mix which is handy having it on the body pack.The limiter and lock functions I tried but honestly don’t use.The lock function I don’t use as it is going to lock in a frequency and I don’t want to forget that it’s there in case I change frequencies on the fly.The limiter function seems interesting, However it’s really for loud playing and even though I’m a drummer I try not to crush my ears so I can’t say that I’ve fully realize the potential of that feature.However the future I do love the most is the EQ function. It is a simple on/off setting which I thought it would be an equalizer with various mhz bands however, but it’s an on/off.( you can see in a picture) I was a bit skeptical at first but I really like what it does to the tone. I don’t know how to better explain it then equating it to the magic button when editing a photo.It just makes the music sound better :-).In general it seems like the body pack has the same clip as the other unit, but the body pack itself is more substantial and feels a bit more solid.People have complained about the clips and other reviews I’ve read, yes they are a bit flimsy, we haven’t had any problems yet however we are largely not moving these too often they are kind of “permanently” clipped on the guitar and bass straps and the rest of us clip them on our belts at each session.Again if you were actively touring you would probably have the body packs in a small case as you see with any other professional band.Also I forgot to mention it comes in a nice padded custom fit case which is really nice. ( Included in a picture)I love when equipment comes with proper carrying cases.I haven’t had any trouble with either unit so I don’t have any experience with Tech Support with Phenyx Pro however I can tell you this is the second piece of equipment that I bought from them in the endeavor to get my band fully wireless it has not let us down. It does come with a one-year warranty so that will be there in the future should we need it.In summary it’s a great unit with awesome sound, lots of features, and plenty of channels to choose from.I’m always happy to answer any questions if you should have any.