Not as experienced as others, but I hope it isn't too selfish of me to say that I think I do write okay XD
Then again, I'm a bit messed up, I enjoy writing under pressure (essay exams or procrastinating on a research project). I remember having completed my english research essay about 3 hours before it was due. Writing from beginning to end took about three hours, but I had my research material prepared from a previous time. Needless to say, I got 87% on it, and I was like "Wtf?" But happy. I think I have to talk myself into actually doing stuff on time though, as I will have a heavier course load this time around. And yes I do plan to major in English XD
I can usually make good judgements of people's writings early on. Even forum posts can be a bit of a giveaway. I may use the odd 'lol' or emote of sorts, but I couldn't lower myself to writing like I am SMSing.
Btw it's cool that you're from NZ, I was there for 10 days, as it was cheaper to fly through there from Australia (was there for 9 months) to fly back to Canada, than to fly direct from Sydney.