Proof is in the pudding! Wait for rain and then go visit the camper! If no leaks, you're good. If indeed the floors were fixed, I see no reason why it could not be a good camper.
About mobile techs? The reason he frowns on them is because they are a competing business. Of course he's going to down-play them.
After you jump up and down all over the floor like an excited 5 year old at Christmas time, pound on the walls like a 3 year old throwing a fit and make sure they are solid too.
Then play Santa and get on the roof and see how it feels!
If all seems good, no squishy floor, no soft spots on the roof, no walls bending or moving in-an-out, then call your mobile tech friend and pick it apart.
Have fun! You've got not nothing invested yet, except your interest.
