Not sure why you say this. The Geekbench ratings for all 2011 quad core i7 MBPs is much higher than the dual core 2013 13 inch rMBP from here.
Not for the single core test (which is "most things" like I said). The lowest new 13" has a 32-bit single core score of 2659. The 17" that the OP is looking at has a 32-bit single core score of 2484. Note, the scores I used are the ones on the list.