My family takes a Disney trip every year, whether it be the Land, World or a Cruise....we can't get enough Disney.
We spent 2 weeks in California last August (spending 4 days at Disney) and thought it was a great time of year to go (3 years before that, we also went in August). Living in the midwest we are so used to the heat and humidty. The heat in California with NO humidty was wonderful. You would step in some shade and the temp would go down 10 degrees.
One of the things we like about the Land is that all of our favorite rides we like in the world are also at the land. So we spend our time comparing the little differences and some we like better at the world and some we like better at the land.
Having the 2 parks so close together made it so easy to hop back and forth depending on our moods. Since the 2 parks are not connected with fastpasses, we could hold one for each park at the same time. So before we would leave and take a break for the day we would get a fastpass at each of the parks and then when we come back all rested....we have no lines to stand in.
This year I will be at the world in July....yikes, talk about crowds and heat....I get them both and will love every minute of it
No matter what you choose, you will have fun no matter what!