As far as suction it gets a 5 star, but giving it 3 due to various issues.  First, opened box to find internal box all smashed up but tapped.  No big deal since all parts there and nothing broken.  Next, instructions (ripped) said to adjust wheels to lowest level so vac head off the ground max, you'd think it came that way but it didn't, it was at its lowest point.  I tried it out and it was sticking to the bottom occasionally enough it needed adjustment.  Okay, simple, loosen some screws, adjust and tighten, but it wasn't.  While they unscrewed okay, only about half would tighten at all.  All the others would just spin (I'm not sure if this was a used unit sold as new and someone over-tighten, since amazon has a tendency to do that) even when trying to push in so nut catches as much as possible.  Had to go get a channel locks to hold the small edge to tighten, major PITA.  Once I did that it flowed much better and sucked well.  However, coming down off the wall in forward stroke this unit flies away from the wall, and is very hard to keep it against it.  I was going to adjust wheels for more suction but then I see the problem, the metal poll connector doesn't go vertical so you have to put the poll in an extreme angle making it a PITA as well.  So I reversed the connector so I could go vertical and next vacuuming we'll see if that solved it.
As far as suction it gets a 5 star, but giving it 3 due to various issues. First, opened box to find internal box all smashed up but tapped. No big deal since all parts there and nothing broken. Next, instructions (ripped) said to adjust wheels to lowest level so vac head off the ground max, you'd think it came that way but it didn't, it was at its lowest point. I tried it out and it was sticking to the bottom occasionally enough it needed adjustment. Okay, simple, loosen some screws, adjust and tighten, but it wasn't. While they unscrewed okay, only about half would tighten at all. All the others would just spin (I'm not sure if this was a used unit sold as new and someone over-tighten, since amazon has a tendency to do that) even when trying to push in so nut catches as much as possible. Had to go get a channel locks to hold the small edge to tighten, major PITA. Once I did that it flowed much better and sucked well. However, coming down off the wall in forward stroke this unit flies away from the wall, and is very hard to keep it against it. I was going to adjust wheels for more suction but then I see the problem, the metal poll connector doesn't go vertical so you have to put the poll in an extreme angle making it a PITA as well. So I reversed the connector so I could go vertical and next vacuuming we'll see if that solved it.