I did this route in May for the first time. I'm sure there are scenarios where it could take 90 minutes (and there are a number factors: gate location, checked/carryon baggage, train schedule, your ultimate location to drop off luggage) and it is good to plan that it might, but the estimated time for me (to my hotel ) was a little over an hour and that's about how long it took.
I was really happy with this, since now it usually takes me a fairly predictable hour to/from any of the three airports.
