Regarding the noise concern, there should not be any difference as long as the pump is installed properly. Regarding your cycle rate, it may actually increase since it will be emptying your basin quicker. It's always best to keep your cycle rates to a minimum when possible. So if the M53 worked well for you and you never came close to flooding, I would suggest keeping that 1/3HP pump in place. IF that M53 had difficulty with demand at any time however, then I would suggest increasing to the 1/2HP model M98.