As you can tell by the lack of answers, there's not a whole lot out there and not much (any?) real experience with us here.
You're probably going to have to rely on search engine results and reviews, doing your own research.
I did have the chance to play with a PineTab. When I went to order one, they were out of stock. They haven't been in stock since, as far as I know. I just checked and they're out of stock right now. It was snappy enough though the default OS was still in beta. Last I knew, they'd installed a different OS on it (Ubuntu, with Touch? Maybe?) and it was their daily driver. So, maybe wait for that to be stocked again.
That ends the entirety of my experience with Linux tablets. Sorry that I can't be of more assistance.