On July 20, 2015 at 15:06, mdavej said...
They are identical now. The old Ultimate is a previous model and used to lack the ability to control home automation devices like the "Home" model. But they have since added that capability to all Ultimate hub based remotes via a firmware update. Sounds like you aren't doing any home automation anyway (lights, thermostats, security systems, etc.). If your old One has a swollen battery, Logitech may replace it with an Ultimate for free.
Not sure what you mean by swollen battery. There may be a meaning there I'm missing, but if not, again, the only reason I need to replace the Harmony One is because of it's lack of RF capabilities. Plus it has started to become sluggish.