I've used a DBV and own an SSV, and the SSV won't get you much more performance wise. It can pack a little bigger punch hit wise, with a more concentrated air stream, but the DBV is a little more predictable in its hits. It also takes just a hair more care during use, due to the hands free connection. I like the SSV heater angle. I place it where it's convenient and easy to use, so I don't regret buying it over the cheaper model. But if $ is a factor, or you like the hands free setup, I'd go with the DBV.

I have both the Launch Box and iolite too. Each has different advantages in regards to portability. The LB does better with small amounts, as far as efficiency. The iolite is very stealthy, except in quiet areas where the hissing noise during reheating would be an issue. The LB is a very simple design, and should be much more reliable over time, and it has the best warranty on the market-unconditional and open ended.

I'd go with the DBV and LB over the iolite or SSV alone. You get really high value and both a home vape and a portable.