I’ve got a Roland cloud subscription and I definitely think it’s useful and way more convenient than vintage gear approaching 50 years of age. I also have the arturia v-collection and think this last update made the Roland synths (Jupiter and Juno’s) sound way more alive and better imho than the Roland versions. They are both pretty good though. You can get the same dsp emulation in the Roland boutiques/Aira as well if you want hardware knobs to twiddle.

Iirc the 808 and 909 in rebirth were sample based. The 303 was nice and squelchy but not quite a perfect emulation. Lots of fun to play with though. I remember spending hours in college playing with rebirth.