To answer the subject line question, I don't think I would choose to go back to Smart Things.
I have all 3 generations of the ST hub, the V2 and V3 are currently present on my network, and are managing the Majority of my Zwave devices at the moment, mostly because I'm taking things slowly, moving a device to HE and writing the RM Or Simple Lighting rules for it, and then relaxing, drinking some Whiskey and then moving on to the next.
I bought the HE because of local control, and I'm quite willing to put up with a few growing pains and difficulties to disconnect myself from the Samsung experience.
Don't get me wrong, with my minimalist sort of setup, ST worked fine,and I wasn't hugely dependent on the cloud, my automations generally worked during internet outages, and everything came back up after power outages.
What killed me on ST was the transition from Smart Things to a Samsung account, the ridiculous classic vs new app, and the inability of the rules engine to handle multiple conditions (or my inability to make it do so anyway). Oh, and transitioning from my V2 to V3 hub was such a nightmare, I shudder to even think about it!
I also don't like the confusing ST developer interface, and much prefer how HE is organized with code (app) and device driver sharing.
The ST app is a nice convenience, but I think (hope) the Dashboards will mature into something much better.
As long as HE continues to work (and improve), and most importantly doesn't require the cloud (other peoples computers) to do my home automation, I'm probably likely to stay. If it starts to fail dramatically, I'll probaby move towards HomeSeer.