I have a 2010 non-ESA - I am using an Antigravity LiPo (Lithium Polymer) AG16YTX12 battery, much bigger than stock and WAY lighter. It turns the motor over very well, no problems. I have not had any problems starting in the cold either, but then I very rarely see below 32ºF (0ºC).
Very happy with the battery - it does not need a tender. Spec says parasitic drain is <0.2 volts per year.
Pig In The City - 2010 BMW R1200 GSA Adventure
1996 XL1200S Sportster - a temporary insanity (restore job, will be for sale shortly)
Webmaster BMW Touring Club of NSW