Pros: The mobile app is awesome. I can read a bar code on anything I'm eating and it will add the nutritional information for me. No bar code? The database is crazy. I mean they even have every kind of kroger brand cheese the place sells.
You can track your food and fitness. I still like having Endomondo for the GPS in case I walk outside.
At the end of each day it tells you your calorie count and gives you a message that says something like "if every day were like today you'll weigh XYZ by this date" I think that's cool
Cons: It doesn't let you track what you want to track like Spark People. For instance, I want to see how much protein I've had on my phone. But it only shows calories. I have to log into the website to check my protein.
On that same note, Myfitnesspal figures out what calories I need. My nutritionist told me to try for 800 a day but not to worry so much about that yet, and just too focus on getting protein from real food. Myfitnesspal says I need 1400+ calories and keeps giving me a warning for eating too little. I think it would be cool if these sites let you pick your weight loss method.
All in all I'd say it's pretty cool!!