I vote a suite, just because it's guaranteed vs. the hotel screwing up your two separate reservations and you ending up on different floors...

When I have a suite, I know we'll be together. I hate when we're told "but we kept you on the same floor!" grrrrr!

The extra bathroom is nice when they're older but for this age, you kind of want to control the bathroom yourselves (no one gets in there, leaving the water running, slips, etc.)