Now, I'll start off by saying that I'm mostly a SU contributer. SO is normally just a resource I refer to, and I rarely contribute there so I am not very familiar with some specifics of the site.
Just today, I have had one edit rejected and one almost rejected on the same answer. Those edits were to fix a broken link and bring some content into the answer, as per previous discussion on link-only answers. In all cases, the reject reason given is as follows:
This edit is incorrect or an attempt to reply to or comment on the existing post.
Now, the first edit. It was purely to fix a broken link. As far as I know, that is most definitely encouraged. That got two reject votes before it was finally approved, with a rather non-descriptive reason that doesn't even apply.
The second edit, I could see getting rejected as making too big of a change. However, again, I do not see how the edit would be 'incorrect' (again, previous MSO discussion encourages it!), and it is most definitely not an attempt to reply or comment. (In fact, on the reminder about substantial edits, I decided to add more by quoting the link content - it just happened that the first was approved in that time, splitting the two edits up.)
I have asked this question for two reasons. Firstly, I would like to know if my edits are in fact considered incorrect in SO. To my logic, they seem perfectly valid - especially the first one, fixing the link - and they are accepted as good edits on SU to the best of my knowledge.
Secondly, I would like to suggest that there is a problem with SO reviewers not really paying enough attention to what they are reviewing (this follows on from previous problems with the new review queues, which resulted in the introduction of audits). SO is a much bigger site than SU, and I am sure it gets far more edit suggestions. At the same time, it has far more users to perform the reviews - there should be no excuse for rushing through them.
Then again, perhaps discussions and decisions on meta are not visible enough, leading some to be unaware. In any case, this is not the main point of this question, and really should be split into another question if it warrants further discussion.