I am looking at purchasing a Polaris 280 and one web site recommends the 280 w/tracks for vinyl pools. They indicated that the tracks provide better traction in vinyl pools, however they do not offer tracks on the 380 model for vinyl pools? The cost of the tracked 280 is actually less than (-20) the regular 3 wheeled 280 which, to me does not make since. My question is, are the tracks that necessary, and how well does the 280 with tracks hold up? If the tracks do not work well can wheels be put on instead? I would think the track would introduce more friction for the pump to have to overcome?