Glad to see you didn't make a definitive answer.Short answer : it depends. I think you have enough info here to make an educated decision.
No doubt it's currently the best battery available, but at a very basic cost level analysis, if I can get a $165 battery with free 3 year replacement that works out to $4.58 a month for 36 months. Meanwhile an X2 at $270 with a 5 year warranty is basically the same at $4.50 a month.
I've never paid more than $170 tops for a battery in my fairly old life. So if I'm going to spend $270 on a battery it better last a hellva long time and occasionally make me breakfast in the morning. haha