I switched from Restylane (used twicearound mouth and naso folds) because it never seemed to last more than 3 months and the second time, the pain and bruising was surprisingly bad (same MD as the first time and not a problem then).
I am now on month 4 of Perlane and so far, it is holding up OK, but I am doubtful of the one year potential they claim. I also was at a new RNP and told her of the pain from the Restylane, and she said that was because the MD didn't wait long enough for the anesthesia to take effect. She gave me the locals and I waited at least 30 minutes and this time, there was little-no pain, even though the Perlane is a thicker product, and no bruising.
I will use Perlane again in a month or two and see how it goes. Even though these products don't last indefinitely, I will use them as long as I can afford to and will not opt for the knife.