Just get the one with the 7200RPM drive since they are the same price. Otherwise, all specs looks to be the same.
The only problem I came across regarding switchable graphics is that the nVidia GT 550m in my Lenovo Y470 "disappeared". Windows 7 could not detect it. The only way to get back use of the GT 550m was to restore Win 7 back to factory settings. Simply re-installing the drivers for the GT 550m did not work.
In the research that I've done, it seems to be an issue with the nVidia GT 5xx series that causes this not very common problem.