In regards to serviceability & quality; Probably the Olympia SGE line. Those were made for heavy, professional use & with regular maintenance in mind. Olympia SGE 40 is probably the "flagship". 
Every other criteria is subjective. Personally, I prefer the feel of electric type bar machines over the Selectric. 

If I want electric, I go full electric. No half measures. I like the "business like" feel of them. 
But I have that same issue you describe with Selectrics. Just doesn't feel much like a typewriter to me anymore. 

I agree about the disconcerting feeling of using an electric with power return.  I understand why they're built that way - to keep up with fast typists - but still, it's jarring.  Like Pete, I much prefer one with a manual carriage return lever.

One thing that keeps electrics behind manuals (for me) is the fact that they're not autonomous.  With a manual, it's just me and the typewriter.  I can take it anywhere.  An electric is dependent on a whole host of infrastructure and people to keep the grid going.  If the power goes out, it becomes a useless brick. 

The imprint from an electric is more consistent than from a manual, removing some of the human element - but is that necessarily a good thing?  I find myself without an answer as I can see advantages on both sides.  

Question?

Do you think the Smith Corona Electra 120 is the best balance between retaining everything about a manual typewriter as possible, while having the benefits of being electric?

Thanks, Jim.
Yes, I've watched that video and a number of others by Duane on YouTube about that "family" of Smith Corona's. They seem to be the best of typewriter technology up to that time, whether manual in the Galaxie series, etc, or the electric/manuals like that SC Electra 120.

I recently watched the video on the power return repair on the SC Coronet, etc, and it used nylon gearings and an added level of complexity that I'd rather avoid. So, no "power return" features for me.

Keep warm
Snowstorm this weekend. 17 inches predicted.
k