It's all about the lid
The problem with the contigo ones is that while it provides a good thermal barrier and liquid security it is pretty complicated which doesn't make for easy cleaning.
The zoji ones are good. I used to really like my simple 300ml lifeventure, also had a cheapy issue /bcb copy. I liked the simplicity of these and the fact they were pretty good at heat retention for 300ml. Don't know if they have gone downhill in recent years though. Bought a couple of LV ones recently and will report back in due course.
I'll give klean canteen a look. Wasnt aware of them before. Cheers.