The "Vesuvian Bespin" proposal here is that scientists have found high enough in the Vesuvian atmosphere, atmospheric pressure and temperature are potentially comfortable for humans to go without (or at least much less) extensive life support (ignoring chemistry problems mentioned below). So, Earth would be kind of the ideal place test such a construction before committing to going to Venus. If you want easier 'floating' (making certain assumptions about the technology one might use to do that, e.g. we haven't invented anti-gravity machines), you go down to denser atmosphere and trade off against ease of human habitability. Which would seem to defeat the purpose.