The Rize X is 73 pounds, the Aventon Pace 500 is 50 pounds. The Pace 500 is $1500, the Rize is $2199. With relatively cheap upgrades to the Aventon you can get the weight down to about 45 pounds. I looked at the Pace 500 for myself and my wife. I ended up going with a Yamaha Civante Road Ebike but will be buying the Aventon Pace 500 for my wife.
The Pace 500 is an 8 spd not 7 spd. It uses the new Shimano Altus group set which is about the equivalent to Acera which shifts about as good as Alivio.
You can go 20 miles at 20mph with the throttle on the Aventon if you want but that defeats the purpose of an Ebike. Why not just get a scooter.
The Rize bike needs a 52v battery due to its weight.
I do agree that a torque sensor is better than the cadence but to have to lug around a 73 pound bike ugh! Try pedaling that if the motor dies on a ride.
Get the Aventon for your wife, she will be happier with the reduced weight and the better handling. You can drop even more weight with lighter tires, lighter handle bars, seat post, seat, and stem. Once you have the adjustable stem dialed in, buy a rigid lightweight stem. The new Altus group set is decent. You can upgrade the derailleur to an Acera but I think that they are pretty similar based on professional reviews. You even get 180mm hydraulic brakes.