I thought I'd weigh in here since I have used the nutrition program...and I think the silence from other Cathletes is telling.
I paid for a trial period and found the program just frustrating. The "grades" are good on one hand but I find the depth of detail adds to my own OCD issues and it was too easy to get wrapped up in trying to get a good grade, as it were. Another time-suck that I didn't need.
Now, don't get me wrong, I love Cathe and all she does. I'm pretty sure this nutrition software is made by someone else. It's just too clunky for someone like me.
I've used sparkpeople, and weight watchers, and most recently myfitnesspal.
I think simpler is better. I prefer a program that will let me watch my macros at a glance. I also want to have a lot of control over reports, particularly over time - which is where mfp falls down IMO.
Overall I think the best thing is to find one and stick with it. None of them are perfect but many of them are perfectly fine. Tom Venuto is coming out with a nutrition tracker that sounds interesting. But again, it won't be free but it will be more fitness focused than the more generic programs.
HTH.