Once upon a time I worked for a weekly newspaper chain in southern Dallas county. We had an 'automobile review writer'. A big part of his job was selling advertising space to auto dealerships.
He got to review / test drive a lot of cars. He didn't get to pick which cars. The dealers always gave him the newest models, or the models they were having trouble selling.
He really wasn't able to say much negative. Not a paper policy, but because the dealers would cancel their ads.
From what I've seen of RV reviews it is a little better. The manufacturers pick the models that will be reviewed. They set limits on where the rig can be taken and what type of roads. They define the options, and they have veto over who gets to test / review their RVs.
Might be a fairly decent job, but it has its limitations. Articles have to be finished, and meet a word count/ length requirement. Not too short, not too long.
Probably a normal 40 hr per week job with review camping being unpaid time. Probably in the 30k per year range.