[davidmat]

My top 5:

1) Poor separation between content and presentation

2) Way too many features enabled by default.

3) Bulleted lists don't always indent in predictable fashion, which is annoying

4) When cooperating with a few people things go really bad, really quick (track changes, I'm looking at you). For example: header styles start to change, lists of tables start randomly missing items, references start failing,..

5) Numerous other layout issues that slowly drive you mad each time you have to use word

[eavc]

I guess it's all I've ever known, really, but now that you point those things out, they are irritating.