ssv has 3 heater cover choice types (classic (This one seems to be the FC personal choice myself included), GonG(same as the DBV), and spherical GonG (has to be held like the classic but makes a better seal than the classic)) + ssv also has the downward angled port so no worry about losing hash and concentrates in the wrong direction.
based on this If i was to get one again, I'd get a classic ssv. over a dbv. you can get them for 15% off using FC discounts. that's what i did. or buy on ebay a "blemished" ssv for 190USD it's sold directly from 7th floor still, but you don't get customization options this way or the travel bag.
the element inside both units are essentially the same thing.