Karl,
Those models are the same in CA...last I knew. The new 200DX-DV is now just the 200DV. Just call and ask for any models you don't see. May not have been readded to the site.
The new 60S has a higher OCV than the 50S if I remember right. And it does have added cut capacity. But if you are asking if a 50S would handle most items on a day to day basis of an average customer, then yes, it will. The 60S would too, but you wouldn't have too much to worry about up to 1". On the 50S, above 3/4" you will see a drop off up to 1". And 3/8" to 1/2" would be the target daily maximum cut use for the 50S for best speed/quality combination. On the 60S, I think it would be more like 5/8" to 3/4".