As it happens I have the prototypes that Steve cast last fall, one of which, was the version selected for the rod seen above. It's been quite a while since I've cast the 15' 7/8 4pc but to the best of my recollection there is a measure of similarity. Both have softer, deeper flexing actions that make them really easy and fun to cast. The 16 has enough give that a 5lb fish would really bend it nicely but still has the bottom for a Clearwater B-run fish. A real sweet spot for rod strength. Both are very relaxing rods that are, like Steve mentioned, great fishing instruments and not just nice casting tools. As far as differences go I would venture a guess that the 16'er above is lighter in hand, and possibly swing weight, than the 15'er.
It's great to hear from guys who recognize the fishing advantages of longer rods, like mendability and line control, lifting sink tips easily with a single spey, even on mid and long bellies, etc. Haven't got my notes right in front of me but as I recall the prototype worked really well with an Aerohead 8/9, and WinterAuthority 70 6/7, (don't have a 70 7/8 at the moment but I'll bet it would also work like a champ), and Gaelforce 63 7/8. I would also venture a guess that a SalarFinder 45 F2 8/9 and a 15' tip would also be a spectacularly effective fishing combo. There are a lot more line options out there than most guys would think.
Steve, congratulations on developing a great rod. I am very much enjoying the prototypes ( both the green and red).
I see you're a shvingger too!
Bruce and Walker North America - Pro Staff