Hi George,
No personally I do not fly an Evo for one simple reason. I already owned two MC 4000's when the Evo first appeared. I would have had some difficulty persuading she who must be obeyed of the need of a new radio
However, I know lots of people who have them and all seem to be well satisfied with them. My personal experience and that observed over the years of others, has been of very high reliability. I personally have never had a fault in 18 years.
The mixers are a little unusual. Has as been pointed out, once you have "built" a mixer you can't change it without affecting other model memories were that specific mixer is used. However, you can use that mixer again for another model providing it is configured the same way, so it is a double edged sword. On the one hand it is something you have to be careful with (there is a warning before you alter a mixer, so you can't really do it by mistake). Conversely it saves a lot of programming time if you want to use that mixer configuration again.
More to the point is the overall power of the mixers. instead of a mixer just having the ability to mix two input channels it can mix five. This is a very useful capability on complex models like jets.
Regards,

John