I did Crossfit for about a year with a co-worker. We loved it but didn't dedicate as much into improving my diet as I did in working out. Sadly I was doing one of the Open workouts and went WAY past where I should have on a workout and really hurt my lower back. Also ended up getting a hernia (not really that big of a deal) and had to take a break. I haven't gotten surgery for the hernia yet but plan to this winter and I might go back to Crossfit next year.
The instructor for my morning group ended up opening his own box. He's a really solid guy and preached 'go at your own pace' religiously. If you manage the weights you lift, the form for each workout and your own pace then you'll be fine and Crossfit can be very effective because it's really working on mostly 'everyday moves' that we do. Where people have problems is when they go too fast, have bad form and/or try to lift way too much and they get injured.
Now, is Crossfit good for golf? I think there are likely other golf-oriented workouts that might be a little better but, like I said, I think Crossfit develops core muscles that we utilize a lot in our regular daily activities. So I always felt like my ability to play better on the course related to my endurance, which will improve as you do any work out regiment, but I saw myself doing regular daily stuff (i.e. work around the house, etc) much much easier while I was doing Crossfit.