I think you're going to have to elaborate more. What's "better"? Louder? What kind of tone are you going for? Are there brand names involved here?
Looking in your profile I assume you're talking about the Hartke B90 and the Hartke Kickback 10. Well, there is only a barely audible difference between 90 and 120 watts if it's into the same speaker, and 15"s are usually louder than 10"s. The aluminum cone on the 10 just gives a slightly different tone. The B90 is most likely a bit louder.