Hi. I am adding my observations to your review after a EWR-ORY roundtrip on LEVEL (in Economy from EWR to ORY and Premium on the way back because the price difference was minimal at the date I wanted after factoring in the cost of the meals and a checked luggage).
I found the experience in Economy to be similar to what I found on Norwegian last summer (putting aside the fact that Norwegian stranded me for three days on the way out and flew me back on a wet-lease): the planes are new and clean, but the food is subpar for the price. I agree that the Economy seats on LEVEL are more comfortable than Norwegian's.
Premium was in line with what I have encountered in US domestic first class: large seats and the flight attendant was taking good care of people. I cannot compare to Norwegian as I have never taken Premium on Norwegian.
The low point of the trip was the fact that one has to take a bus from the plane to the terminal at ORY. On the way to ORY we were in the back of the plane and literally had to wait 30 minutes to exit the plane after the doors opened as apparently the buses had to do multiple rounds between the plane and the terminal to unload everybody. And on the way back we got to board the bus first as we were Premium but then had to wait until the bus was packed before leaving the terminal and it reminded me taking the Parisian subway line 6 at rush hour in the summer (for those who don't know line 6 is aerial and it's unbearably hot inside when it is hot outside)…
In any event as Norwegian stopped flying EWR-ORY and that route is more convenient for me than JFK-CDG I think I will continue to use LEVEL in the future provided they keep their prices reasonable (my roundtrip at over 1K per person was quite expensive). If they increase I will go back to United even if that means having to endure CDG or might give La Compagnie a spin...