I like the 100 size the best. I also have a 78 which works OK but it doesn't walk as fluidly as the 100. The 78 wants to jump around some where the 100 walks perfectly. I purchased a 65 but I couldn't get it to walk much at all -- even on 4 lb test. I haven't tried the 115 but I bet it would work well like the 100s.

kc