Generic patches here. They stay on for about two days, then the adhesive starts to fade; the thing practically falls off after five days, no matter how careful I am, and I find myself constantly pressing it back against my skin. Not impressed.
That said, they're cheap, and since I'm not going through insurance for that particular medication (it's a dead giveaway and will raise huge red flags with my therapy and other meds, all of which insurance does cover right now), generic works well enough for me. I'm definitely getting some estradiol into the system - less than one month in and the effects are noticeable. I can make do for now.
Brand name patches seem to have much better staying power.