Responses from md4emitters

How much difference between new/refurbished amps and amps that need more than a tuneup?
Making a statement that my new CJ 2550 I bought from you blows my older 240w CJ 2500 out of the water in every department. I guess if there was a question asked it would be " at what point does one need to replace or have an amp serviced?" 5000 ho...