Is HO scale, mostly due to the huge selection and my aging eyes, otherwise it'd be N scale. (PS - 1:100 scale would make so much sense in so many ways, but that's another story.)
Has a large scenery:track ratio. Way larger than the average Thompson MR Diorama mag's photos of typically two-foot wide sidewalks where a couple of fat people walking in opposite directions wouldn't be able to get past each other (unlike in the aisles of their model railroads, where such matters are taken much more seriously than actual real life scenery).
Has no track radius smaller than 48 inches. Not very practical, I know, certainly not for me, but there's just so many layouts that look absolutely wonderful in the magazine photos until that fatal picture of a long train rounding a horribly and unrealistically sharp mainline curve shows up.
Must have a continuous run option so I can visit, unwind, forget my workday problems, and just sit and smell the ozone.
Does *not* have onboard sound, which seems to mostly sound like an alkaseltzer installed into a glass of water. Room sound has a whole lots more potential than in train sound, IMO, when it comes to toy trains. Bottom line is that it's all about the physics of sound - you just can't put a realistic sounding loudspeaker into an itty-bitty model. As it is HO in-train sound is nothing more than a cute little joke IMO, or an evil marketing ploy!
DCC probably is very cool but also is a needless additional expense for a "lone wolf" modeler such as myself. Besides, achieving sensible and practical "analog" wiring has always been kind of a fun project for me.
Best I can do right now is an industrial switching shelf-type setup with an automatic back'n'forth in place of continuous run. Oh well, life is an endless series of compromises, eh.
Tejas Pedro
"What, me worry? I'm voting for Kinky!"