The Fidelity Amex is about the only true 2% cashback card right now, and as such, it is a good value. I don't know that there's much to talk about, other than to say, yes, 2% cashback on everything is hard to beat. I'd say most people who are active on these forums are posting about other cards in an effort to get over 2% returns using miles and other points.
It certainly is possible, but it takes some work. Also, it helps if the travel redemptions you want line up with the high value redemptions. That's where the point valuation discussion get fuzzy. It's not useful to you to be able to get over 4 cents per point at a Park Hyatt if you don't want to travel to certain high cost cities that have a Park Hyatt.
Figure out first what you'd like to do with your points. Then decide if there's a strategy that allows you to beat 2% cashback.