IMHO it comes down to what you're hoping to get specifically from the SLRO's being released.
If it's just about the amount of likes/overall popularity of the scene, then 75% of it comes down to casting and the rest is down to the theme/quality of the shooting/etc. Put Melody Marks in a scene and it'll get a shit ton of likes, streams, and downloads regardless of what it's about.
It seems like it would be pretty straight-forward to tell which actresses or combos would drive a high favorite/stream/download rate, if that's the main goal. Between responses here and in other forums to casting suggestions, I would imagine it being pretty identifiable anyway.
I personally can't think of a single SLRO scene with an actress that I thought would be super popular, but then wasn't. The opposite is definitely true though- seeing an actress and thinking "hmm, don't know how the response will be to this one" and then seeing it sit pretty low in favorites/likes.
If it's about the above but ALSO about drawing in new subscribers, then I think some of the linked scenes are great examples of more "niche" styles/demands that may not be as popular with the overall base, but may be unique or rare enough in VR that you'll draw in subscribers for them. I should say that I'm using the term "niche", but that's not really the best word since none of the linked scenes are really at all niche in the grand scheme of things. Just can't think of a more appropriate word. So I think they definitely have their place, though obviously I'm making a lot of assumptions here and don't know whether they actually drew in new subscribers.
I do think that now that we know polls are a doable thing in the forum that there could be some good opportunities of gauging interest/response and getting some useful data using those, though obviously it could pose some challenges in how to set up or keep it ongoing.
But this is all just my 2 cents. Even with the above scenes that were "less popular", SLR continues to be my #1 in huge part due to the SLR Originals you guys put out.