I don’t know where Audioman is coming from, but in terms of resolution, an integrated may very well be the most transparent and best combination, since everything is in one chassis and the entire design is thought out as a whole. To my mind the limits are usually power and size related. I personally think having fewer gain and buffer stages is an improvement over more, and having an integrated makes this happen.
Usually, if doing a ss/tube combo people go with tube pre’s and ss amps. Giving the tube warmth and color, with the solidity and extension of ss amps, but make yourself happy!
I do think if you are thinking of switching the integrated you should consider the new generation AR as a fine choice. Take a while to warm up though.