advantage of seperates vs integrated

I have been thinking of a change to seperates but.. I was weighing the advantages of a seperate amp/pre as opposed to using integrated (I have use of Classe CAP 151 right now). What I'd like to go to would be all Solid State Audio Research to mate with my CD 3 Mk 2. The additional questions would be; would the ARC SS provide better bottom end to the Apogee Slant 6 I lsten to and would it also provide a deeper and wider sound stage advantage for the investment of approx. $2200-$2700 post sale of existing equipment as I listen primarily to soft rock, new age and jazz? Currently the sound is very good and very smooth, would the change be worth it? Thanks for the opinion.