I would do as suggested above, have your buddy fire it up. Grab a couple of chairs and get comfortable and try and imagine having a conversation around the RV, then go inside for a bit and "test" the sound in there. If you can tolerate it and your neighbors aren't going to have fits over the noise you and your generator are making go for it!
We bought a Honda Handi a few years ago, we can have our gen running just outside the back of our unit and barely hear it (in eco mode) from sitting under our awning and can't hear it in the RV. Noise is going to be huge for you AND your neighbors.
Good luck on your purchase.
Dan