From 2003 to 2007 I used an Airtronics/Sanwa M8 and also upgraded it when the very first Spektrum modules were released. Great radio. Then I sold all my stuff and took a break from the hobby.

I just recently got back in the hobby this year. I bought the Flysky GTB3 and I am totally satisfied with it. It does everything that my older M8 did. The cheap $8 receivers are also an added bonus. To me I see no difference in performance. Build quality might be slightly on the lower side as I can tell the plastics they use are slightly cheaper...but the difference is so slight that it is negligible. I haven't used the newer M11x etc, so I can compare it to those radios, but like I said, the GT3b does everything I need just like my older M8 radio.