Better for what? Theoretically the 700s will roll better over bumps, but big fat tires on the 26"rims will be smoother than skinny tires on the 700 rims. If the the size 54 feels "a lot more comfortable" then there is really no reason to buy the 56. The 54 with 26" rims will probably have more room for fat tires, fenders, and a third water bottle than the 56 with 700 rims. My suggestion is to look at how the complete bike feels when you ride it, instead of obsessing over the physical dimensions of one or two parts.