I experimented a bit more. I am evaluating these VSTs as something that I would be willing to pay $20-30 per month for to use. The official, Roland-branded, approved reproduction of the original is worth something, but:
The performance stutters now and then even on a less than 1 year old high-spec iMac, the graphical user interface can be stretched to a big screen but looks very grainy, it just does not feel like a go-to VST synth somehow.
I think a Roland branded/approved collection of reproductions of "legendary" synths can work, but it needs to be 99% perfect for $20-30, 90% is not good enough. Also, maybe Roland should considering integrating with Native Instruments NKS. I think this could be a great business model for Roland, but also for Yamaha, Korg, etc.