I currently use Dropbox for backup of stuff on the laptop/access to that stuff on my phone etc etc. However, Drive is pre-installed on my phone and I’m wondering if I’m duplicating apps for the sake of it.

Anyone gone from one to the other? Does Drive look/work like a ‘normal’, folder on the laptop like Dropbox does?

Yep pretty much. Drop a file in and it syncs to the cloud and other devices.
I use both for some reason!