LordCrash The dangers are:
1) We may end up making decisions based on unreliable data - a skewed data set with a small sample size.
To illustrate my point, look at the number of likes compared to the number of comments below:
Even the less popular videos consistently get around a hundred likes or more. But half the videos don't even have a single comment. The more complicated you make it for users to give feedback (e.g. by asking users to type a comment or by asking for 9 different scores per video), the fewer responses you will have. Your responses will also likely be less representative of the SLR community as a whole. It will gravitate towards those who spend the most time on SLR, or very likely mainly a few hardcore users.
And there lies the risk - and it applies even more so to new models with just one video. What if you cast a milf and you only get 1 response from somebody who's not into milfs? Or what if one hardcore user hates your storyline/costume/camera angle but most other people couldn't be bothered rating? Now you are pressured to make decisions based on a very limited sample size.
The alternative is feedback from hundreds or thousands of users. Better yet, if you have access to total time watched, you'll be able to see how well the new model/storyline/costume/camera angle performed across every single person who viewed your video.
This is especially a concern for smaller groups/fetishes. E.g. @someoneX isn't into typical US porn but instead prefers studios that shoot more authentically. But users who prefer typical US porn are going to rate someoneX's favourite scenes poorly, even though they're not the niche that the studios are targeting. So now the niche studios get poor scores and are pressured to move away from shooting the scenes that their audience likes.
Instead of relying on feedback from a few users who may not be into your niche, you can effectively filter out those who aren't your target audience using likes/total time watched. Those who aren't into foot fetish simply won't like/watch the video. But you'll get hundreds of people who do.
Then you can check how your videos compare to others that serve the same niche. If others consistently perform better, what are they doing differently?
2) It could clutter up the UI
Final thoughts
Anyway, you clearly have strong opinions about this as do I. I don't think there's much point discussing this further. As long as we take the reviews with a grain of salt and the UI doesn't get cluttered, then it's not a problem.