Boondocks 8 Year Old Bourbon Finished in Port Barrels has mild ethanol and oak nose with a slight creme de cacao liqueur aroma from the start (maybe that's tawny Port that I sense). Additionally, there is a very mild spice too the longer the glass sits. After the first sip, the oak becomes more prominent.
You get a moderately strong oak flavor on the palate with a slight rye kick. However, the taste is "skinny," with no viscosity. Sadly, I do not sense much of the Port in the taste. Having lived in Portugal for a few years (2 hours from Porto) and being a huge fan of Port, I was looking forward to the Port finish.
The finish is relatively short, but that's where the crème de cacao liqueur flavor reveals itself again, along with oak. However, most of that is overshadowed by ethanol.