I am thinking of this mostly because I get the red battery symbol fairly often and I haven't been able to track down what is draining the battery. A few times I have seen about a 800 mA load on the battery with everything off, cycling to ready and off again often stops whatever it is, but without checking every time I shut the car off it could go dead on us. I am not sure what the heck it is, but it is intermittent and Nissan says it's not there. With a larger battery I wouldn't be as worried, heck it could likely handle a 800 mA load all day. The stock battery is sub par as far as batteries of similar size, sort of like the ecopia tires
So I figured if I was going to replace it I might as well up size it as well. As far as weight if the extra 5 lbs of a larger more capable battery I think it is more than worth it. And going with something other than lead acid adds a lot more $ for the capacity.
My wife takes short trips all day, about 3-5 miles a hop, usually about 60 miles a day total and if she comes out to a dead car it will be bad for me and her job. So it is worth it to me to upgrade the battery.