I personally thought HESI was harder, and here's why. At the end of taking HESI, you get a printout of areas you're weak in, which means that it covers a broader spectrum of topics for evaluation purposes. It lets you know what to "beef up" on when it comes time to take NCLEX.
That being said: NCLEX didn't ask nearly as many of the OB/GYN, electrolyte imbalance effects, etc. questions that I admittedly stunk at. In some cases, whole categories of stuff were left out. *cheers silently* Depends on the luck of your randomized draw, I guess.
You should be sitting pretty with that score, but still, study as if NCLEX will give you nothing but your worst topics. *smiles*