I have 4 receivers a Duo2 - LX3 - Gigablue Quad + and the Mut@nt and I have to say in all Honestly that my Favorite has to be the Mut@nt, I even like the remote although it dose have it's little quirks, like the record button being directly underneath the power button and the colored buttons being at the bottom, but I soon got used to it after I had switched it off about 3 times trying to record a program and pressing the power button by mistake I tend to have more problems using the remote for the Quad+ with it being a universal remote, if you press the TV Button to get the channel listings it stops working because that is for your TV you have to press the special GIGA Button to get it to work again and press the FAV Button to get the listings and they are very small buttons so you really have to be precise when you press them and not ideal if you use it a lot like me I might program my Harmony 650 for the Quad + because I never use it otherwise
The Mut@nt is fast it seems much more responsive than the Duo2 and I never thought that I would be saying that 6 month ago and another thing in the Mut@nt's favor is having 4 separate plug-able tuners, that way you can set it up as you want to, I love my Mut@nt and it is the best receiver that I have ever owned