Interesting topic @palallin
I will say that I am partial to the ZW. For me, the draw came much before I ever used one. I received a Lionel 2035 and tender along with a variety of K-line cars as a Christmas gift from Santa when I was 5 (in the early 90s). It was more than magical - however, it wouldn't run on the dinky and forgettable 45 watt 1015 transformer that was in my older brother's set.
I listened closely as my dad and grandpa discussed needing a larger transformer and there was something called the ZW. The biggest, the best, the most powerful, capable of handling 4 separate trains at once. Whistle control, directional control. This was my new holy grail! One of my uncles lent me a transformer during that Christmas season, but I had my eyes set on the next year and what I needed Santa to bring down the chimney. Well, I think my dad saw my enthusiasm for it and didn't give Santa the pleasure of gifting the great ZW. Sometime in January we went to a local train guy's basement - and low and behold - there it was - a ZW. Green light shining and two handles that could simultaneously turn a boy into a man and a man into a boy.
After the visit, a sat with the ZW in my lap on the ride home. I don't think I blinked a single time while staring at that beautiful circle L logo. I couldn't believe that I was finally about to operate my beautiful 2035 with this masterpiece of engineering and design. With as much anticipation as there was, you'd think there would be a let down when you finally had the opportunity to use it. Oh quite to the contrary, using it was even better than I thought it would be. The smoothness of the handles as the carbon rollers made their way over the coil, the springiness of the whistle controller, even the light hum was satisfying as you were harnessing the electrical power coming out of the wall. So for me, it's hard to beat the ZW.
I've also got an LW and an RW which are both quite handsome in their own right, but nothing surpassed the ZW for me.
I see what you are saying about the KW looking more like controls you would find in an actual train. I also love the look of the postwar American Flyer transformers because they look most like a train throttle to me. I've never owned one, but I always liked the one with the 2 meters and the "Miles per Hour" text on it.
