Apparatus with ground glass joints is certainly a bit more expensive that individual pieces held in place with rubber bungs. But the expense is worth it. Have a look on e-bay you may well find apparatus quite cheaply there. If you look after it, like everything else, it will last forever, unlike rubber, which perishes over time.
Anything that distills over in your "rubber apparatus" will be pure, unless it is an azeotrope, but even that will be pure! The whole point of distillation is purification so having stuff remain in the pot is ok. The trick is to know where to terminate the distillation.