I think you've stumbled onto a good niche idea there. Too many reviewers are busy reviewing stuff like ProVaris (excuse me while I look at my feet and whistle). The kind of smaller things fall in between the cracks a lot of the time. Looks like you're going to go ahead with it, which is great. When you find a niche idea if you don't start doing it right away, someone else will 
As far as what to do first, I'd say go with hardware. juice is kind of the great equalizer because it costs the same whether its in an eGo clone or a Darwin, and there are a lot of juice reviews out there already. Maybe if you could do something to start meriting out the best juice deals out there, that might attract some viewers.
I also agree with the other poster about changing up the intro a little (of course I know nothing about making videos).
Good luck with the new project!
As far as what to do first, I'd say go with hardware. juice is kind of the great equalizer because it costs the same whether its in an eGo clone or a Darwin, and there are a lot of juice reviews out there already. Maybe if you could do something to start meriting out the best juice deals out there, that might attract some viewers.
I also agree with the other poster about changing up the intro a little (of course I know nothing about making videos).
Good luck with the new project!