In which way?
Shields essentially uses all the same filters and rules that you get on uBlock and they are constantly working on making improvements. I know on Desktop and Android, Shields has worked flawlessly for me on pretty much all websites. The only struggle I have is on iOS versions, but that’s due to Apple’s restrictions of how browsers and all work.
I would be curious to hear how you’re saying Shields hasn’t worked as well for you or what features you’re saying are available in uBlock that you feel are missing for Shields?