*Floater*:That's in my PADI EAN32 table so I'm sure it's tried and tested by plenty of divers, though that table requires a 3min safety stop at 15 ft for this dive.
The NOAA EAN32 table gives 100 min at 60'.
http://www.ndc.noaa.gov/dp_forms.html
I played around with decoplanner this AM. It gives 5 minutes total stop time for a 60 ft/90 min dive. As you back off the time to 70ish minutes the deco time goes down to a total of 3 mins.
I guess if I had a particular goal needing 90 mins to accomplish it might be worth it. I' cold at 60 mins anyway.