Personal recommendation systems all have tradeoffs. It's just the nature of curation as an intangible endeavor. You can love "Scarface", "Heat" and "LA Confidential" but still find "Casino" boring ;)

More on such tradeoffs in a recent case study from DeepMind on Google Play Store app recommendations. Even they acknowledge the same techniques that surface 30% cost efficiencies in data center cooling, may not be completely applicable to "taste"

https://deepmind.com/blog/article/Advanced-machine-learning-...