The Flo-Rite works very well. Before I got it, I had a hard time telling if there was too much water or not enough. There was no way to get my head in there and I would have had to disconnect the batteries to get them out. During the travel season I add water monthly.
For what it is, it does cost too much. I still find it worthwhile because I don't have that much time to maintain the coach. Now I can get the watering done in 5 minutes and move on to something else.
Grant