I'm another happily in the Ego ecosystem - works just fine for my ~0.5 acre mostly flat lot. I have the 20" non-self propelled and it largely does fine, but can chug if I let my Bermuda grow too much. Batteries are fine - I've had the same two or three batteries for coming up on four years with no issue - I can generally mow, edge, and blow just about the whole thing on one charge. I also have the multi-head attachment with the trimmer, edger, pole saw, and cultivator attachments; no real complaints with of them.
I do wish I'd gotten the 21" deck on the mower, as that has a few more blade options. It's also not the greatest at bagging clippings.