The commute one - 700c wheels but folds. Arrived in good condition and works fine - we live up a big hill and it coped with it. Bit of work on long uphill stretches but better than with no assist and coped fine with my husbands 12 mile each way commute with a charge at work.
I had the non assist Big, then the mountain curve. Both were built like tanks, and I carried large kids and lots of shopping in the mountain- once I carried my boys, my friends twins and the friend had a backie on the rear rack.
Funnily enough, I've been there with my own kid carrying saga. I'd agree with the previous poster that putting a rear hub motor on and upgrading the brakes is your best bet. A mid motor is fab on hills but unlikely to prove cost effective for you.
Hi, I used to have a crank powered cargo trike but the kids have outgrown it. I have just picked up a cheap Argos Ebike and I'm building up my confidence on 2 wheels again.