I was wondering if anyone had any experience with the (they go by many names) long board/straight line sander/ air file and which one I should get. It seems like I remember some poster saying to avoid the ones with 4 bolts holding the pad on and to look for ones with six bolts. Is there a reason why? The ones with 6 bolts are 120 plus bucks where as you can find a "cheaper" 4 bolt version for under 40.00. What is the difference? From what I can tell they both have a 1 inch stroke and a 2 piston design and are around 2500 to 3000 spm. I have the sandpaper on its way and am waiting to find out what you guys think before buying one. I have a DA sander but it doesn't quite cut it for getting the door panels and hood as straight as possible. It doesn't have to last forever and I am not doing it for a living so if it only lasts for this car resto or longer that would be fine.