As a rule, Rob, 2-1 exhaust systems such as the D&D FatCat, D&D Boss, V&H ProPipe, Reinhart 2-1, etc. will produce more pounds and ponies than a hybrid (2-1-2 as on the '09 touring models or the older touring models where the rear header split to the right and left sides) exhaust system. The difference will be even more pronounced when comparing a 2-1 exhaust system to a true dual system (take your pick of brand here).
This is pretty well-known among those who are looking to squeeze the most performance out of their bikes.
Keep in mind, though, there are other factors to consider. A 2-1 system will provide the best performance out of any particular build. However, without other mods on the CVO 110, you are never going to wring all the potential performance out of that powerplant. For that, you'll have to do head work, valves, cams, higher compression, etc., etc.