My twins were three months shy of three when my daughter was born.
Overall, I think it was a good spacing, but in hindsight I think I expected more of my boys than what was fair when their sister was born. She is now older than they were when she was born, and I simply couldn't imagine another baby.
They were almost potty trained when she was born, so I had little time with three in diapers. We purchased a really nice twin stroller with big bicycle-type tires, and with the baby in the sling, I was able to get out more and take walks.
In terms of baby care, I really enjoyed having only one, although at first I felt that there was somebody missing. Baby care, with just one to nurse, or get to sleep, or change, was just so much easier.
Now, they are close enough in age that they play together.
Negatives of having them as close as we did are that the boys weaned earlier than I would have liked (just after two years).