I use an MTH Z4000 for the trains, and Z1000 for the accessories. 2 issues I have had were the 14V accessory tap on the Z1000 was out of phase with the main 18V connection. I also do not like having to zero the Z4000 throttles before turning the transformer on - a pain when using DCS. I'd prefer using the Lionel 180W bricks with my TIU if I could find any.
Tom