Given the other reviews here, decided that getting two batteries would be smart due to the freshness issue, in case the first one didn't last as long.  (My original battery was worn out.)  It's been a couple months now and the first battery is still going strong where before I needed to have the charger with me to finish my calls.  Price was a major factor here compared to retail and I wanted to wait a few months before considering a new phone.  The much lower price made this plan easier, giving me plenty of time to consider the next generation of Razr.  And if these batteries quickly died in the short-term then I didn't lose that much in the deal.