Suggestion: Write as if your audience isn't full of English majors. Several reasons for this:
* There are lots of really, really smart people who aren't so good with English but still make good decisions and can help you. Don't alienate them.
* There are lots of really, really smart people who speak another language first and English second or third. Don't alienate them.
* Some people might find long words or complex language to be annoying. You might not like people like that, but again, sometimes those people are the very ones making important decisions, and it might be best not to alienate them.
You can still be correct and interesting without being complicated (look at this comment for example), and I'm sure your grasp of our language is good enough that you can be straightforward and simple without dumbing down your message.
In short, make people feel good about themselves when you're around, and they'll feel good about you.