If that happened to humans we'd be pregnant for 27 months and be awakened by crying babies most nights for several years. Potty training and the terrible twos would last three times as long. Eventually we'd have (and be) teenagers for 24 years. Let's not even think about how long we'd have to deal with hot flashes and, for some people, the aches and pains of old age might last for about 90 years.
Thanks, but no thanks.
No wonder we've never heard any more about those experiments! You don't have to be a scientist to figure out that it's better to leave the long lives to the worms.