Brian:
I enjoy both
Typhoon Lagoon and
Blizzard Beach for different reasons. TL includes the cool Shark Reef attraction where you can snorkel in a safe environment as well as its Crush 'n' Gusher slides that are best described as half roller coaster and half slide. Blizzard Beach sports a chairlift that allows you to see the sights below as well as a longer family raft ride than Typhoon Lagoon.
What makes me recommend Blizzard Beach, hands down, for families of toddlers, though, over Typhool Lagoon is it's children's area
Tike's Peak that provides longer slides than TL's and nearby seating as well as better visuals of my children on the slides. It is also my go-to water park for families with pre-teens as well because of its Ski Patrol Camp that offers activities that are more adventurous than the "kiddie" areas yet don't have height requirements--and danger--of the taller slides. As I
mentioned to Sarah from Massachusetts last week, there's simply more to that matches the skill levels of kids under 10 at Blizzard Beach.
Wishing y'all a magical vacation!
Whitney