Noise handling - FS100 is probably the BEST low light camera out there. The 700 is noisier at higher ISO's
Dynamic Range - seems to be slightly less, could just be some of the pre-production model tests not attempting to perfect it
Image sharpness/resolution - I have an untrained eye but watching some tests I could tell, especially at higher fps, that the image seemed soft and not as crisp as some of the fs100 footage i've seen
Compression of 120fps and above - well, looks pretty bad. Probably vimeo or my connection, but it looked blocky and very typical of AVCHD.
I guess for skiing and a 15k budget it would be alright, Resolution issues mean very little for web delivery, and the high fps/built in ND's are nice to have (but please dont overuse slowmo, for the love of god)