I don’t think I have ever heard nice things said about Android tablets.
I like my Galaxy Tab S4. It even has ANT+, though newer Galaxys (phone and tablet) do not. But the S-series isn’t cheap. I usually use the tablet for streaming and my phone (Samsung Galaxy S10, also has ANT+) for TR.
I’ve seen the lag thing in old tablets, I think it’s because the flash memory actually gets slower rather than the tablet being slow in the first place.