I have two Z4000 transformers on my larger layout (four loops - 12'-by-8') that have been in operation for twenty years without any problems. Until recently I had also been running my smaller single-loop layout (10'-by-5') off one of the Z4000s on the larger layout. With the closure of MTH, I wanted to have a spare transformer and recently purchased a third Z4000 (new - made in 2018) that is now running the smaller layout. I run conventionally - mostly MTH engines but also quite a few Lionel Legacy. Satisfied with the service I have gotten from the Z4000s. In your case, why not buy the more recent transformer, although, from my experience, I don't think it makes any difference. If you're concerned about future parts availability probably better to buy the ZWL.
MELGAR
