Hi, I had to work with DW platform for 5 long years. My boss just recently threw the DW3 unit out the window (hope there was nobody down there) and got Medit Blue with Exocad. You wouldn't believe how easier my life is now. The DWOS software is just no match. If your boss is willing to pay for DW7, he'll get much better value for his money with some exocad based setup. Unless he gets the DW7 super cheap and even then I wouldn't say it's really worth it... As for scanning times, I believe latest DW7 takes about 80 seconds to scan an arch. Yes, it has 30 slots on multidie, but it scans the dies one by one. Still uses one single laser line to read the surface. You can make and drink several coffees in a row during the scanning phase. I had a chance to play with DW7 before making a switch to a different platform, just to see if an upgrade to a newer unit would make sense. After a few minutes I was sure it wouldn't. DWOS version 6 didn't make an impression either. As for the DW7/DW3 difference, there's not much there. DW7 isn't really that much faster than DW3 and the value of the huge multidie is questionable.
I can get better results in a shorter period of time with Exo now.
Long story short: don't recommend.