We had On site do our tubs and tile white (they were 70s pink and blue) four years ago when we moved in. We were and are still very happy with the results. It looks fantastic and looks like it was always white tile and grout from the beginning. Only cleaner. We also had them do another house that we purchased as an investment home and later sold. That one was even more dramatic as we had them do a very old dingy bathroom over white shower enclosure and tile wall - I think the sink too. It was such a huge improvement. The cost is very reasonable and about one tenth of what you'd pay to redo the tile or tub or sink. I think it was the actual owner that did the job and he was meticulous about preparation and taped off absolutely everything that shouldn't be refinished and literally not one drop ended up where it is not supposed to. He showed up when he said he would both to do the quote and then the job. They do it with what looks like a paint sprayer but I guess the solution must be a more permanent substance than paint that adheres to tile and tubs. We were happy when they did it and we are still happy 4 years later. Shows absolutely no signs of deterioration. Hopefully will last for many years.