I have several N scale T-Trak modules and they are quite a bit smaller than the Ntrak module I started and never finished (it actually ended up becoming a small layout). The biggest (or should I say smallest) difference is the supporting structure. Also the on the N scale side, a single module is roughly 12x12 Granted there is not much you can do in that size but it lets you make a diorama that can have trains run through it. Not having to worry about where to store the legs (on or off the module) having the module small enough that one person can manipulate it for construction or storage is also a huge plus. The HO modules we used in the club I was in in VA were not easy to move alone and storage took up much more room. All and all I am really enjoying working with the T-Trak format and if I was still doing HO I would prolly gravitate in that direction as well.