Well I did the brats just as planned and they were done at 2 hours. I ate one as is, and the rest I kept warm on the grill on the upper rack while I cooked the other food. The ones finished on the grill were maybe a tiny bit better though I would be hard pressed to tell much of a difference. Both were excellent, and I'll definitely do these again.
Next time I would probably just go with straight cherry wood vs the cherry/hickory mix.