I am a terrible critique partner. Or I would be if anyone asked me to help. I've had requests, but I've had to respectfully decline. I am a better beta reader. I can do broad perspective, an overall "Good job" or "Maybe take a look at chapter three." But I cannot point out specific problems with someone elses work.
This is a little odd, because I want someone who will do that for me. I have never once been offended or hurt by big red notes in the margin about parts of my MS that don't work, don't make sense, or just don't belong at all. I trust my friends/partners opinion and almost always take it.
But to do that
However, if you are looking to try out your new red Sharpie any time soon let me know...I'm sure I've got a few stories waiting to be critiqued within an inch of their lives.