I hadn't purchased anything, in HO, for some time... until, last Monday. While, at at local train shop, looking for some add-on parts... I saw an Atlas HO Canadian Pacific(burgundy and grey) Alco RS-3, that appealed to me. In all the years, that I've had O gauge and HO model trains... for some reason, I never ended up getting an Alco first-generation road switcher. That ended, on January 2, 2017; when I purchased, an Atlas HO - Canadian Pacific, road number 8439, DCC-Ready RS-3(from the latest run, 2015).
Not only do I like this locomotive model; but, it provides an unexpected benefit - for some reason(s) it provides a positive perspective, re: the other locomotive models, in my collection. It kinda acts as a mid-range benchmark... re: my other models. The RS-3 is not one of my best models, nor is it my least favorable... it's just a very nice unit.
When a number of models are of a similar quality... it's sometimes hard, to pick a constant winner; I seem to fluctuate... over time, re: my opinion. I don't know if other people judge their equipment; but, for as long as I can remember - I've always looked for the best... in things.