I had the same problem with my first and only batch that I used bourbon soaked oak chips in. The flavor was way too harsh and tannic. Since then, I've only aged in a 5 gallon whiskey barrel and have yet to have one that is over-oaked. I'm also going to attempt using cubes at some point that have been soaked to see how the French oak does in comparison to American.
Kegged 10 taps - Citra Pale Ale, Session Saison, Blonde ale (Nitro), Cascadian Dark ale - X2 variations, German Pilsner - X2 variations, Vienna lager, wheat, Bourbon bbl aged RIS .
Primary - Lacto/Brett Saison, lacto/Sacch Saison, Lacto/Sacch Sour Stout.