Personally, I am very pleased with my Max Lumi (which has been superseded by other models). It was quite expensive, though, but I can say I have used it very often for five years and expect many more of it, still. However, because of its size, I don’t often bring it out with me. I primarily use it for studying at home.

But if you don’t need the largest size (13"), the smaller ones are less expensive. If I were to replace mine, I’d probably go for a 10" one. I think that seems the right balance of size for writing notes and portability.