RealTrack 143/144 just derails all the time though (And I purposely went about making a new layout to be as level as possible to it could cope)! They are also very fragile/hard to take apart to put decoders in! All my Bachmann 2nd gen DMUs are really reliable, look good, hardly ever derail and have easy DCC installation [wring a DCC decoder in is much easier than it is to open up an RT model]! I haven't tried any 156s yet, but their livery process is so random nothing has appealed to me yet! I would rather wait for Bachmann for the 158. Personally, I think the old tooling for the 158 is fine for now and they should expand the range instead...
Note that I do not think RealTrack is bad, it's just their modeling decisions aren't to my full likings, where as Bachmann is much closer to my full likings.