Don't choo worry bro, the VC can deliver full-on stoney extraction with the minimum of material. Combine that with the ritual of heating the cap & the natural feeling of using fire, and I think overall, you will be satisfied.
But, as you know, it is not a plug in desktop, it is in fact tiny & butane powered - when you hold it you will likely know that you made the right decision. And it will probably add an extra dimension to your vape collection . . . . the Evo is definitely a most awesome & powerful tool, but the VapCap is ingenious, and for it's size, it has the ability to slap you surprisingly hard, while at the same time being all cute & highly tactile
And there's really not much to it technique-wise, but if at first your eyes don't bleed, try and try, and try again!
You will be rewarded!