If you are the type of person that wants to know ahead of time exactly what amperage you will max out at before hitting the pedal then I would say that the older style 200DX is not for you. From what I have seen on here the newer 200DX machines have went to the industry standard panel controlled amperage and have done away with the pedal pot. If this is true then I don't see any reason why you shouldn't get the 200DX. Likewise, if the pedal pot is not a problem and they haven't updated the machine it is still a good buy for the bucks.
Everlast Powertig 200DX
Miller Synchrowave 200
Miller Dynasty 300 (Work Machine)
Hobart Handler 210MVP
HTP Microcut 30