the people running optimas probably never ran any other battery to contrast between the two. Personally, I've dealt with the hc2400 along with r-t optima and y-t optima. For the dollar, i'd go with the kinetik. Obviously, the hc2400 is superior to the y-t optima because its almost twice its ratings in every aspect(also bringing up my score .8). My next battery i will be testing is the powermaster d3100. Seems people swear by it, so i will put it up against the hc2400 along with the two yellowtops.....
if you can expand your budget, look into deka along with powermaster. I agree with 350z on the order of batteries.