I still have my original porcelain flavorizer bars, but may replace them with stainless when they rust out. Depends on how long they last and the price differential then. I replaced the porcelain grates with stainless after my original ones started to develop rust spots after about a year. My fault, I'm sure. Probably brushed them too vigoriously.
As to which is better, only you can decide what is better for you. IMHO, stainlesas steel makes sense for grates as it will last forever. People will tell you that stainless grates don't sear well, but that has not been a problem for me. YMMV.
If you don't like the food, have more wine