I’ve a few Soundtraxx (steam) & one Dallee (diesel).
I’m considering a Mylocosound for Thomas…I also have one NIB Soundtraxx Diesel I thought could be re-programmed to operate w/ Steam Sounds 
ETA:
My Dallee is one of the boards that Aristo offered at a lower cost. It wasn’t until I had installed that I realized it was minus a few features from a ‘regular’ Dallee board. The horn is the main culprit…meaning it cycles through a different horn blast instead of allowing the user to use as they wish. Instead of blasting your way through a crossing you may have a reverse horn, or a fwd or a long blast. My kids don’t really care, but it’s always been a sore spot for me.
Dallas (Dallee) offered to program like his normal board for about $40, and I may eventually do that once I get running again. It wasn’t his fault/problem that Aristo sold them w/o informing the consumer properly of the limitations of the board. I would have bought one of the regular boards for the higher cost if I had known then…
My Climax and Shay had Phoenix boards and they were nice too…though they are both now residing elsewhere.
For the Analog Battery/RC dud(e) like me, Soundtraxx Sierra was the board of preference…