that is why I like ESU. They are NOT the quickest out of the blocks, but they DO support their stuff for MANY years.
The ESU ECoS II console is the current model, but they keep the updating to ECoS I and Marklin Mobile station up to date, and with the same features as the ECoS II. of course the old ECoS and CS1 does not have the color screen, etc, but the software has the same features, and bugfixes. I do not think anybody else supports their stuff for as long as ESU does.
The ECoS also has the wifi connectivity and an android app out for your smartphone and tablet. they also published their protocol, so anybody can code their own interfaces to the ECOS command station.
As for backwards compatibility, Roco is not the best, I agree, but their FIRST dcc system (Roco Digital is Cool) was a mess, and I would also pretend it does not exist. they DID bring out an adapter cable that allowed it to be connected to the later LocMaus system, but I would strongly suggest you do not waste your money. the current z21/Z21 system IS 100% backwards compatible with every thing else that preceded it, including in descending order the MultiMaus wireless, MultiMaus, LokMaus3 and LokMaus2. also the various versions of the turnout control keyboard is 10% supported. as for the boosters/command stations, again, just the original Digital is cool is incompatible, the other boosters all work happily together. the start set command stations actually ALL function very happily as either a command station OR and add on booster.
for me, the biggest problem with the EURO stuff, is support. there is just not much of it in SA... as for digitrax... I will reserve comment