When we were building our club layout, we used a ZW to power the lights on the layout. In 2002 I read an article (probably the same one) on using outdoor lighting transformers for layout lighting. I went to Home Depot and bought three 120 watt Malibu 12v units. They worked great, and didn't get hot like the ZW did. By the time we finished the layout, we had 7 of these units under the layout.
All these units were the type that had a rotating 24-hour disk where you could insert plastic tabs to turn the power on or off at different times. Since we power the whole layout down at the end of the day, I just removed all the plastic tabs and left the switch in the "on" position. The units available today have digital timers so they are not as noisy.
The 120 watt Malibu units were about $40 back in 2002. Today the equivalent Hampton Bay 120 watt unit is about $60 at Home Depot.
I have purchased several more units over the years for different layout projects. Oddly enough, only the last unit I bought (about a year ago) was actually used for outdoor lighting.