I'm no expert, but I did stay at a Holiday inn all last week.
My first thoughts when someone says they want more power is they want to push their equipment beyond its designed limits. If you just want more power, instead of replacing the pump with a bigger one, you might be able to just adjust the relief and gain a little force. My second thoughts are, by saying the equipment is getting lazy, folks thoughts automaticly go to their hydraulic pump. My suggested first course of action would be to check the flow and pressure settings on the system. The laziness might not be in the pump, it could be bypassing in the control valve, cylinders, or any hydraulic circuits. Throwing on a new pump wont cure whats wrong with the rest of the system. Not checking the pump first could result in buying and replacing an expensive part and not fixing the problem. If you dont have the equipment to do the proper checks, it might cost you a few dollars to get someone to check it for you, but that would still be cheaper than buying a new pump only to find out that wasnt the problem in the first place.