I like it for internet radio, but when I'm sitting, I'm usually at my computer, and that plays better without draining the battery... the same about MP3s.
I find the screen too small for comfortable reading.
No Exchange support, deal breaker. Embedded app doesn't handle well the thousands of mails in my gmail account.
Lack of Firefox add-ins is the final nail in the coffin.
I'll stop here, and remark that all those experiences you further listed are shaky and require some contortions, and I'm not seeing anybody stepping up to bring them on to consumer level.
I moved away from windows about 8 years ago because I was tired to have to babysit the systems, and I wanted to have something that just works. Weird as it sounds, Linux was such a platform. But NITs are not .