I have no personal use with either mill you listed, however we use the VHF S1, it cuts emax without a flaw. We achieve margins that don't require thinning in the blue state. The Dental Cam software sucks though, its as locked up as it comes. The IMES 350i was a great work horse but the spindle required frequent rebuilds. It was run with SUM3D though which was a huge plus. We chose to stay away from the DWX-4W as it is more of a chair side mill, I don't see it being reliable for big production numbers. It does have a Jager spindle however and can be used with SUM3D. If you're not planning to do a ton of emax, it may do the job and a decent price point, but I don't believe it can cut Ti. We had a sirona mill that was constantly breaking down, needing parts and Sirona was a pain to deal with. The 5x400 is a great machine for emax and some Ti, but it isn't recommended for continuous use with Ti. I guess it comes down to how much material you want to do right away - do you want to spend as little as possible to get in the game and upgrade later, or spend the bucks up front and not have to replace down the road? Most of these machines only have a recommended 5-7 year lifespan anyway...
