I got my passenger swivel mount from discount van truck online. I had to raise it by 2". I used some steel square tubing for that. I also had to grind a little on one edge to completely clear the floor as I had new floor put in and did not want to risk it hitting. It wasn't too much extra work, but I had the steel and tools to fabricate the 2" lift. It really improves the space inside. My girlfriend likes the extra height too. It isn't a real smooth swivel, as I have to adjust the recline and front to back seat position to swivel it 180 and clear the armrest/door. But it goes ok. We swivel 180 when we park it, then don't touch it until we leave. All said and done it is worth the money and effort for me. I wont do it for the drivers side because I don't want to be 2" higher in the seat while driving but I am happy with the results for the passenger side.
2003 Winnebago chalet E450
Also, 180 sitting on it, yes, you are closer to the floor and the floor is basically like your footstool. Mainly this is just nice as 180 makes it feel roomier. Plus the dog likes it...he can look out the window and still see what is going on inside with us.