I finally gave in and purchased the ETS 150/3 and Midi package from Bob Marino a couple of weeks ago. Due to my work schedule I have not been home to unpack it and get a little practice with it. To provide everyone with a little back ground on my next project, I will be using the ETS and RO to prep my sailboat for paint. I will be stripping/removing old paint, fairing, and prepping. At this time I will only be working on vertical surfaces with it and was wondering how to determine what the correct setting is on the Midi. I want to create enough of a vacuum for proper dust collection but due to the high quality of surface preparation I'm looking for I don't want to set the vacuum too high and have the sander digging in. As always I greatly appreciate the help. I might add that Bob was excellent to deal with. He reviewed my order to make sure that all items were correct and also followed up with e-mails within in expedited manner.