This thread is really pretty thorough.
Poor Man's Lightweight Battery
I have run the 16lb Odyssey 680, the 19lb Deka ETX20L, and the 5lb Shorai LFX36 over the last 5 years of TT competition. Because my car doesn't get used daily and has inherent current loss due to active electronics I must keep it on a maintainer or the battery will go flat. If they are fully charged and in top condition they will all start the car. After damage from a few flat battery events they will sometimes not get it done. I recently put a full size AGM back in the car for peace of mind.