We have them on our Bilenky S&S coupled tandem -- but running 9 speed. They've been great over the 8 years and 20k+ miles of riding and touring so far.
They are not cheap, but compared to top line new Shimano or Campagnolo cranksets they are in line -- and IMHO are far better looking and arguably better made.
For a grail bike I'd say go for it.