Rotovap and dual rotovap, Which one is more popular?

Just wondering which one is more preferred by everyone, the regular rotovap or the dual rotovap?

Rotovap with chiller and vacuum pump, a good and simple solution for distillation.Mix the solvent with the leaves, and then recover the solvent to purify it. It is very suitable for beginners. Of course, if you want a more refined result, you will need more machines to solve them.