re: Would you pay off a 6.5% rental?

Without knowing every single detail, I have to go with my gut which is that above around 5-6% is when I would personally rather payoff a mortgage instead of holding cash/investing.

So IMO yes - sell the rental you don't like, pay off the 6.5% rental you do like that your kids will live in someday. Just the overall peace of mind from this move simplifying things would for me be worth it. Factoring in the 6.5% is just icing on the cake.