I had two completely different 81s, here, for a long time. Just now I've found a 75. Will keep looking.
Great level, IMO!
(a few minutes later: woooow, got it! Really great one! So many misleading options. :) )
This level gave me a lot of trouble. There are so many options to try but none of them quite get you to 71. I had to find 6 unique paths before finding the solution... Really difficult level.
