Going to a GFP-715 is a lateral move. Here is a user review that compares 565 to 715...
http://www.audioreview.com/cat/amplification/preamplifiers/adcom/gfp-715/prd_324244_1591crx.aspx
You haven't said what your budget is and what you are looking to gain with an upgrade.
http://www.audioreview.com/cat/amplification/preamplifiers/adcom/gfp-715/prd_324244_1591crx.aspx
You haven't said what your budget is and what you are looking to gain with an upgrade.