Hi, I'm Lady Kyoshoku.
Myself as a beta-reader...Well, I've always been a spelling/grammer perfectionist, even when I was much younger. My vocabulary is substatial, and I have placed in a few spelling bees.
My style...I don't really have one. I do percision spelling and grammer work, synonym replacement, punctutation and occasional sentence structure for those who are a bit...sentence challenged.
Even when I'm just reading a story, I beta-read it in my head, so I'm always getting work done.
I have references from a few years back on AFF.net and dA.
I don't really have any expectations, just that the author is vaugely polite and doesn't get to nosy (Questions are not my favourite).
I'm Canadian, so if you're American let me know so that I can change my MS Word settings.
And if you use this feature, I do know how to use the "Track Changes" feature on MS Word.