Here's one from someone who actually is doing CrossFit:
I'm a member at the CrossFit Palo Alto (CFPA) box (that's what we call the gyms, because they're typically a sparse box-shaped gym). I've also dropped in on other boxes across the country, which I do when I'm traveling.
The #1 thing to know about CrossFit is that while it's a 'brand,' it's not a consistent experience between boxes. It's actually very, very different. Erin's post doesn't make a ton of sense to me because it's as if she's saying "I don't date men, because all men are jerks." Some men are, but some aren't. It's the same with CrossFit. I'm sure that the things she described actually happened to her at a CrossFit box, but they've never happened to me at CFPA.
I've been to boxes where I wouldn't go back. But CrossFit at CFPA has been life changing for me as an entrepreneur. It's one hour, three times per week. I get a very high ROI off of those three hours of commitment. I've been at it for a year now and while I was intimidated when I first started, I've gotten to the point where I look forward to the workouts now. The thing that's great about CrossFit is how it makes the other things you do in your daily routine easier. I'm a new dad and I carry my daughter in a bjorn, which means I have to squat when she drops something and I have to pick it up. CrossFit has made squatting easy, for example.
CrossFit can be disastrous if you don't know how to keep from pushing yourself harder than you should. Everything at CFPA is tempered with weight decisions that are very personal. I've never once felt pressured to go to a higher weight; if anything I was frustrated early on because the coaches wouldn't let me go as high as I thought I could. Some boxes likely aren't as good at monitoring that.
United Barbell up in SF is good, as is Horsepower in LA. Those are the three boxes I've been to that I thought were very professionally (and safely) run. Hope that helps.