Eh, you get more features in the base BRZ, everything else is pretty much the same. The suspension differences are literally slightly stiffer springs in the rear and softer up front for the FRS. That's it. TCS is the same system.
I bought the BRZ because I liked the looks more than the FRS (bumpers specifically), interior is nicer IMO- not a fan of all the red beyond the stitching, material is nicer IMO, headlights aren't an upgrade (HID vs halogens), fogs standard, etc.