If I get a CRZ I will probably use some of the reconditioning methods used by the Insight I folks. From what I understand they have developed a way to charge the battery off the grid (low amperage) once a month and then using a dummy load drain it off. I guess that helps the battery stay healthy. Some folks have gotten over 200,000 miles out of their battery pack. There is also a couple of companies that rebuild battery packs if they are out of warranty and from what I gather that will cost just about $1000. From what I've learned when a pack goes bad there may be only a few cells that are weak or have failed and all the others are OK. Simply replace the bad cells and your good to go again for maybe 80,000 miles or more. There is no need to replace the whole pack unless it is covered under warranty.
Battery anxiety (cost of repair) does not worry me.