When reinstalling your system, try to install Drive into existing folder with the data. Nope, you have to choose a new folder and redownload everything[1]. While this is tolerable for small data accounts, I wouldn't trust them with couple hundred GBs.

While installing Dropbox it just syncs the difference and done.

[1]There is a workaround but you need to think about it before reinstalling the OS (saving some user data or something).