Depending on how far up the foodchain you go on a new amp I don't think that the difference might necessarily be a slap you in the face kind of difference. Many changes in audio are subtle like extended frequency response, more airy highs, warm mids, firm bass, etc.
My suggestion would be to take your intergrated to your audio dealer and audition it with the amp you are considering purchasing. That would give you a fair idea of the difference between new amp/ old amp.
My suggestion would be to take your intergrated to your audio dealer and audition it with the amp you are considering purchasing. That would give you a fair idea of the difference between new amp/ old amp.