FWIW, re: taxes - TrumpTax raised the AMT thresholds so aggressively that the % of folks to whom this applies is probably a lot smaller than it used to be.
I think that really speaks volumes to how relevant it is to join early stage if you want to play the options game - later stage companies _seem_ safer but may not actually be that much safer if you consider everyone already in the investment aggressively driving the price of the shares up and forcing you to risk more on exercise.