Mason and Angus go into creche for one full day a week. They love it now, though it took a few weeks for them to get used to it. Some days they even ask if they can go play with the kids!
I think it's been great for their confidence and independance. Mason especially has benefited from it. He's done a turnaround this year going from shy and introverted to very social and his speech has improved dramatically.
I like it too. I can do stuff like grocery shopping without stress and tantrums.