I also do not wish to re-open any old ZTC debates, but I will say this;
I have recently sold my ZTC 505, and I have down this for one reason only, that is you can only operate 8 functions plus the main lights. There appears to be no way around this.
The latest Bachmann sound locos (37s and 47) have 10 sound functions, and my Howes Class 37 sound chip has 12 functions, so it was time to move on....
I have also sold my LGB MTS systems, considering selling up my Roco Multimaus and Bachmann Dynamis (Both have 20 functions, but cannot read CVs), and I have finally ordered an ESU Ecos, which should be here next week.
The majority of ready to run models now have ESU decoders (Roco, Bachmann, Marklin, and soon the Hornby sound locos), and the ECOS offers the most comprehensive programming and tuning for these decoders. It also offers support for LGB, whichmay need an additional booster to be of full use.
So it is not a case of whose controller is best, but maybe how many functions can you operate with it, and can it be software updated. I did seriously look at the Zimo MX31ZL, but this only appears to have 12 functions, though it is software upgradeable.
Ashley