I went twice to Grote Dorst on consecutive weekends one summer and the first Sunday it was super mellow with only locals and we sat next to some and had a great time. The second Sunday there were a lot more "tourists" -- people ordering multiple bottles and creating a long line. It wasn't as nice but it was still okay since there's room outside to sit. You just never know how it's going to be but I wouldn't avoid it, especially if you've never been.I have been to both many times. Grote Dorst, due to its location and hours is definitely not strictly a tourist place. I would even go so far as to say Grote Dorst has a lot more locals than tourists, but it is just decidedly smaller.
They are very different places, and I personally have stopped going to DHVL largely due to their prices and them having taken on the attitudes of some of the shit lords who frequent their establishment.