I do not lower the temps. Lower temps can allow for bacterial growth and respiratory infections. It's also not necessary. I leave my flexwatt at a constant 92*. Again, all my snakes have had no problems on this method.
Also, I agree that Herpstat is best! I'm saving up for a Herpstat 2 or 4 (I can't decide if I just want one herpstat 2 or two herpstat 4). However, while I'm saving, the Hydrofarms work well enough. I'll be using them as a backup for the Herpstats once I get them.