I have the hammer a3 31 with the silent head. I tried a few other machines and I wasn't really crazy about their inserted heads how they chop at the wood. The hammers Healy coil head cuts more like a gradual knife. At the machine I have to reduce my CFM from 1900 to 700 to keep the shrouds in place. The hammer a3 31 I would consider a great hobbyist machine. It only has one acme thread keep in the planer level. This is a problem if you do not have a out feed and infeed tables that are adjustable or a helper. Heavier longer boards give a gradual snipe as the weight cocks the table a tiny bit. If you go up to the Felder line they have two guide pins to prevent this cocking. They have a little bit bigger of a head in diameter and instead of two rows of inserts they have three rows of inserts. For dust extraction it is 118 mm attachment. I made a quick connect using black 4 inch drain pipe coupling. I turned out the inside of the coupling to 118 mm. I clamp a 5 inch flex hose to the outside of the coupling. No matter what machine you purchase you will want a minimum of a real 600 CFM minimum and a quick connect coupling for the changeover .