I think it very much depends on the company you use. We plan to reglaze a tub in our current house, because demo-ing it is not practical in terms of other concerns. We are leaving a still-perfect old mud job tile surround and having the tub redone. In our previous house, we had an old cast-iron tub from the early 1900s reglazed and it lasted for 15-20 years without problems (it was still fine when we sold the house so I have no idea what happened subsequently, if anything). But there are some real scam guys out there in that particular business, so you really need to research the company you are using, get references, etc. But we were VERY happy with the job at our old house so as long as you find a firm in which you have confidence, I think you'll be pleased.