If its the more toys the better, the Cup is no good to you.
The Cup has no ABS, no ESP, no Xenons, sunday market upholstery, less soundproofing, thinner glass (172 windscreen is UV reflective), no split rear seat, no rear headrests, no boot net, lower powered stereo and speakers, no cruise (only on later 172s in lieu of 6 disc changer which then became an option) erm.....theres probably more but I cant remember.
BUT the Cup is much lighter, has a wider track and firmer dampers and springs and of course the Splitter and Spoiler. And also hapens to be the fastest car on the planet!!! ;-)
Does the Cup have auto lights and Wipers? Cant remember!