I view such conversions as counter productive. If a bike was designed with drops then changing them may upset the overall geometry aside from being an expensive exercise. I know there are tinkerers who relish this sort of experimentation and that's fine if it's your thing but for the average rider it's much better to just buy a bike with the bars you want in the first place. Change to upright and the saddle arrangement will be all wrong, crank position too most likely.