I was reading up on this today. Skuzzy's mention of 90F/s is an Occulus must.
It has to do with the nausea issue. Slow down the f/s and you increase an issue about hand eye co-ordination and the occulus response time. The body over corrects cuz the eyes see motion but theres no gravity response felt.
There is research for a display with a 1700+MHz refresh rate, that will supposedly eliminate the nausea thing. Now if you do not have the nausea issue, gold for you then.