Note: this is one of the novels I'm reading as a voter for the Whitney Awards. My rating and review may or may not be indicative of how I will cast my vote.
Tribunal really didn't work for me. The mixture of Mormon romance novel and spy thriller and post-WWII historical fiction is awkward (and this is coming from someone who very much likes hybridization in his novels). The writing is workmanlike, but in places it falls of the tracks. Everything stretches believability -- which is fine, but it does in so many directions, that it distracts from the core plot. And although relying on coincidences is also fine, they seriously pile up here. There's a few scenes that suggest if Grey had stuck to simply writing a thriller with characters who happen to be Mormon (and, yes, have that Mormonism influence the story, but not have it be all quite so tidy), then it could have been a much better novel.