A Vortex will create and sustain higher heat than 2 Weber char baskets together. You get solid sides, angled, that channel the heat up. "Big difference," is what I think any Vortex owner will say (and I don't own one.) I'm not clear on what a Vortex has to do with cooking a turkey, however.
Lump is always a variable. The charcoal itself should burn hotter, but because you can't necessarily contain it as tightly as you can briquets, may not create more kettle heat.