Dunno yet, but my current batch in the autopot setup are on grow #3, and I will likely use them until they fall apart, which they are showing no sign of doing yet. I may install grommets and lifting handles for the next grow.
I do think that serious care needs to be taken to sterilize them between grows. Not sure how I will do that this time around... The Rain Science bags may be easier to clean than the standard non-woven ones. The latter end up with fine roots embedded in them, and I at least do not have the patience to dig all of them out. I am not sure soaking in bleach would do it, or whether high enough temperatures would be tolerated by the plastic material. Still thinking about options...