Yes, having both scales is for shure more expensive, but these days I can afford it. I gave up H0 when I was a student, living in a small flat. I could only display what I had and not drive it. When finished studying and moving back home, starting to make money short after, I realized Fleischmann and Minitrix was the way to go, with sound locos and short couplings (already as a six-year old I reacted to the unreal distance between coaches). So I built a 210 x 120 cm N scenario, and enjoyed it bigtime. But I could not handle it alone, in order to stove it away when having guests now and then.
I now live in a flat that has dark wood-like planks on the floor. So there's the Rocoline, and the nice thing about that is that you can step on it without breaking anything. Having guests I remove all trains of course.
Right now I am painting/finishing my 160x75 N scenario in my bedroom. Purchased a so-called "hobby-plate". After cutting it is 160 x 60 cm, R2 in each corner. Perfect for my BR23, BR44, BR211 Altrot and BR218 Altrot. Using those green "umbauwagen" as maximum length coaches, and it looks good from a distance.
I like the thought of TT scale, has seen a long train in that scale a very long time ago. I also love those Z scale tracks in a suitcase, but the price is scary.
I love all the scales mentioned here. Pic shows my 160 x 600 (to be augumented from 60 cm to 75 cm) N-system being built. PS: Things are moving fast now. The station will be behind the BR 211/BR 218, just need to add a little wood first. I use this station from Auhagen as it has a good resemblance to Varel (Oldenburg).
