For a first visit...stay with WL. I doubt anyone will be disappointed with the stay. It's one of our favorite places to stay. As a matter of fact, it might be time to book there again....hmmmmm.....
And I don't say this lightly. Having sworn off EVER staying at AKL years before (we made a quick stop by the resort to check it out on one of our trips right after it first opened), we ended up giving in and staying there. Why? It was DD's pick for her 10th birthday. Needless to say, we LOVED the experience so much (had an awesome Savannah view), that we went back for a second stay six months later. It was a great experience and our girls (now 10 and 11) really loved that resort...and so did we.
But WL is special. It's such a cozy place to stay with awesome themeing and an equally great location, especially for a first visit.
Most of all...remember to take time to enjoy to little things on the first trip. Don't worry about seeing and doing everything. That's the fastest way to ruin the trip. Sometimes stopping to watch the street show, or ducks (which can make their own show), or any other random thing you come across can be such a better moment than racing to the next Fast Pass or attraction.
Enjoy your trip...you're choosing between two awesome places...so odds are good.