Ok so my Polaris 380 case cracked and I mentioned it to my mom, who very generously sent me the 3900. I hooked it up and made all the adjustments it said to in the instructions (except cutting the cord yet). The sweeper hose with the new guard that doesn't let it fly wildly out of the water is very very slow (the tail barely wags on the highest setting). (My filter pressure was at 10 about the lowest it gets after backwashing) Out of the box it was at 30 rpm so we took off the restrictor and it's at 32 rpm. It just appears very slow, and I'm just not sure if it's this sluggish new wear may make it useless. I was happy with the old 380 (which I am going to repair for winter use anyway). So I guess I'd just like to hear from anyone with experience with this machine. We had a storm last night and it's been on for about an hour with a good chunk of the leaves picked up. I am going to check it right at 2 Hours and see how it looks. All told though, its better than vacuuming manually.