I have both machines , i bought a DAS-6 as mentioned above, i prefered it when i did a little training course with a Pro , the megs machine is very 'thumpy' with the dual action , Das6 is more subtle imo. I would practice with a DA then goto the rotary but tbh with the right knowledge theres no reason not to jump straight in. Also the DA will correct what a rotary can but it will take much longer. For good advise on these machines goto polishing guide on Detailing World .