I'll echo what Colin has said, your browser won't really notice any speed increase, but if you like to use P2P etc you will get roughly twice the through put down. If you are going for DSL (Not Cable) then generally it does not matter what your downspeed is the upload will always be 256k, 128k upload on cable.
If your looking for a new ISP I can strongly recommend this one :winky: :winky: