Hi, We bought one over a year ago and its been fantastic. It does 4 rides a week in some pretty atrocious conditions and it never complains. Wife mainly uses it and has a medical issue restricting her breathing, she can easily do 20 + miles on it. We live in a very hilly area and its also good on the hills. I really struggle to find any negatives, guess at a push you could say its heavy but so are all e-bikes.
For comparison I also have access to a swytch kit MTB conversion and the rambletta is stronger and faster. My own bike is a pretty expensive MTB with shimano system which will out climb the rambletta but the rambletta is generally faster. You can fit rear panniers easy but not sure about front ones.
The throttle is a great addition and makes the bike so easy to hustle along. As a summary if I want to get somewhere quick and with less effort I will always grab the rambletta. But anything offroad with climbs i will use the shimano bike. Overall its a great bike and the support from woosh is excellent.