I skied a pair of Ficher RC4 WC RC Pro 2015 this season and it is an interesting ski. It is a "master's GS ski" i.e. a Giant Slalom ski which, while still retaining elements of a race construction, is softer and with a bigger sidecut than a full blown race model.
This is in fact Fischer's second line of "master's GS" as they already have a line of dedicated race skis for masters. As these days, the radiuses for Giant Slalom racing have become truly "giant", there is room for two separate classes of master's race skis.
The full master's have radiuses in the 21 - 27m range while the RC PRo are between 18-19m. By comparison, the full FIS race skis are 30m for women and 35m for men.
The Fischer RC4 WC Pro 175cm is 18m radius while the 185cm has 19m radius. I liked the 175cm enough to want to try the 185 and will be testing that next season.
The 2015 skis and newer have the new race-booster plate and more like a D2 extension from the plates, either for vibration damping or to stiffen up the ski as it bends:
It is a fun plate. The ski seems more lively than a 2013 model I skied a few years back.
Of course, the shorter 175cm ski, being shorter both in length and radius, feels like a bigger, clumsier Slalom race ski... which is what it should feel like, so that's a good thing. It is beefy enough to be rewarding for a racer interested in a more relaxed skiing, while stiff enough to challenge an advanced skier to improve technique.
It is a more all-mountain size than a plain Slalom ski, a size which you can bend into a shorter turn, or cruise the blue slopes at speed, in a variety of snow conditions. At 68mm, it is primarily an on-piste ski, of course.
It makes it easy to initiate the turns, it feels very stable and gripy once in the turn and provides a smooth finish.
It is long, wide and beefy enough to smooth out a lot of snow conditions. If there is one characteristic that should be emphasized, is that it's smooth like a big GS ski.
You can do some racing and training Giant Slalom on it, it is surprisingly stable at high speed on ice and can carve a range of radius sets without feeling out of its depth.
It can be overpowered though in a serious, faster set and that's when you'll know you'll want the higher line... I have skied the 188cm/25m of that and it's a different kind of fish.
I have not skied the 185cm/19m yet, will do so early next season and report back.
It is a fun ski. Definitely something an advanced/expert skier should test and consider as a daily cruiser. It can grip and carve down on boilerplate ice and can handle a multitude of on-piste conditions.