Yes the 2014 iS90 63cm wide (93l) is exceptionally good going broad but needs a slightly different stance when pointing in comparison to my 2012 iS97 64.5cm wide (94l?) i.e. the iS97 with its more parallel rails points hard and fast whereas the iS90 is more technically difficult to lock down pointing hard - the 97 easily beats the 90 for upwind speed and comfort IMO. Both very good boards but they do offer very different experiences. The iS97 in very severe chop (open ocean) can become a handful when going for it due to the width of its tail whereas the iS90 is much more controllable.
I also have a 2012 iS117 (80.5cm) and 2013 iS110 (75cm). Even though only 5cm different in width I use the 117 with my 8.6m as my light wind board and the 110 with a 7.8 as my medium wind board sometimes dropping down to the iS97 and 7.8 (which is also a very good combo). Although never ridden one, I suspect the iS107 offers the best of both the 110 and 97, that is to say a 107 would supersede the need for both a 110 and 97.
I've never given the 7.8 a go with the iS90 though. Anyone?
BTW - I'm about 93% of 100kgs