Which is better for hilly streets?

The NIU KQi 100P. Its 600W peak motor and 15% hill-climb rating beat the Joyhis 350W motor, which struggles on sustained inclines.

Which handles rough pavement better?

The NIU. It has 36mm spring suspension and larger 9.5-inch tires. The Joyhis has no suspension and smaller 8.5-inch wheels.

Which is easier to carry?

The Joyhis J078. At about 33 lb it is roughly 5 lb lighter than the NIU and folds in about 3 seconds.

Can I ride either in the rain?

The NIU is rated IPX5, so light rain and wet roads are fine. The Joyhis has no published water-resistance rating, so keep it out of rain.

Is the NIU worth stepping up to?

Yes for most riders. You get more power, more range, suspension and a water rating. Pick the Joyhis only if low weight and simple folding matter most.

The NIU has the sturdier build and better weather sealing, and owners praise its build quality. The Joyhis is fine for light use but has fewer protections.

Joyhis J078 Electric Scooter vs NIU KQi 100P Electric Scooter

The NIU KQi 100P is the better scooter for most riders. It has a stronger motor, more range, a suspension fork and a higher waterproof rating. The Joyhis J078 is lighter and folds fast, but its 8.5-inch wheels and 350W motor suit short, smooth trips only. Owners rate the NIU well for build and ride comfort; the Joyhis has a large but lukewarm rating base.

Choose the Joyhis J078 if you want a light, simple scooter for short flat commutes and you need to lift it often.
Choose the NIU KQi 100P if you ride on rough pavement, face hills, or want more range and a smoother ride.

Prices

Joyhis J078 Electric Scooter: $38.91 at Kitchizon.com (last seen Oct 31)
NIU KQi 100P Electric Scooter: $349.30 at CTT Home & Culinary (last seen Nov 3)
Difference: the Joyhis J078 Electric Scooter is $310.39 cheaper than the NIU KQi 100P Electric Scooter at the latest prices (Oct 31 and Nov 3)