Despite using my gear, I did turn off Bryntroll's proc, to be safe. Like you said, although Frost sub-spec does favor Bryntroll, the results still stand without it. I did do BiS (sans Shadowmourne) tests and it does eventually have Blood Reaping pull ahead... by a whopping 30 dps.
I'm not sure I understand why we would change then. The numbers you cite for using a frost sub-spec and GoBS are 50 DPS and 5 DPS respectively, but then in this post you note the 30 DPS pull-ahead as if it's not something worthwhile.
Essentially, respeccing/glpyinh/potentially changing gear around for a potential 50 DPS gain now seems to not be a great idea if other data shows frost sub-spec falling behind as more gear is acquired. Unless you're really looking for a new way to play Unholy I suppose. On that note I agree - Unholy has become pretty bland in general - it just feels like we're grasping at straws for a new way to spec for a half a percent increase in DPS that likely will get worse with gear scaling.