Worth it IMHO.
Kimme and I drove down to and back from OEM Wednesday. Drove down in Kimme's (my old) NX. It has Progress coilovers with 350f and 250r springs, Octotat rear triangulated brace, and no front strut tower bracing of any kind. (soon to be remedied). My car has the Progress Dan Gardner setup with 450f and 350r springs, Octotat rear trinangulated brace, OEM front triangulated brace, lower control arm brace, and the fender braces. My car, even with stiffer springs rode significantly smoother on the same route on the way home because the chassis is stiffer.