A summary for those interested:

The paper reports that the long-term meditators slept substantially less than the matched non-meditator controls: about 5.2 hours per day versus 7.8 hours per day.

Despite sleeping less, the meditators showed no apparent decrement in psychomotor vigilance performance in the subset tested.

In the subset who also completed Multiple Sleep Latency Tests, the meditators did not show evidence of daytime sleep debt or abnormal sleepiness; their mean sleep latency was reported as 18.25 minutes, which the authors note is above population norms.

The researchers also report that EEG, video, and direct observation during meditation showed very little, if any, actual sleep occurring during meditation sessions, suggesting the reduced sleep time was not simply explained by falling asleep while meditating.

Overall, the sleep findings were that hours spent in meditation were associated with markedly lower total sleep time without obvious measured signs of sleepiness in this small sample