I've ran both, my opinion the RMD is better it will put a sweet down hill bead in pipe then switch over to the ACCU-PULSE mode fill and cap. Definitly go with the pipe pro 450 RFC there awsome we used them on mostly carbon,stainless but it's supposed to be real good on duplex stainless steels. I don't know if your familiar with the benard pipe worx guns they go hand in hand with those machines if you have'nt tried one get ahold of one its topshelf.