Around 7% hills on average, on the 250w, I'm not super fit
7% hills should be ok with the 250 watt and a little assistance from you.
But the other factor you need to consider is range, how far you need to travel. The in-frame battery is obviously small and their claim of 100 km is optimistic to say the least. Since with the low gearing you won't be able to add pedal assistance at 15 mph, the motor will be doing all the work on the flat, which means low range, probably well under half their claim.
I once had a similar single speed folder, an Ezee Quando. It's range for me and all the others who posted about theirs was 15 miles top, for exactly the reasons Cyclebuddy and I have mentioned.
Almost a year later I carried out major modifications which included a derailleur and a 60 tooth chainwheel, transforming it.
So if your needs are limited, short trips only, few hills and none steep, the Ado might suit.
Otherwise best look elsewhere, since there is huge choice amongst the many small wheel folders.
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