I went last year at about 22 weeks. The best part was eating for me!!! Everytime DH would take DD2 and DD4 on a ride that I didn't go on, I'd say "ok, I'll be over at the ______ stand getting_______!" I also hated the sling, I don't think I was big enough, it was just uncomfortable and hot. I took it off and threw it in the trash in frustation!!
Remember after drinking all that water to make a note of where the nearest restroom. Nothing funnier than watching a pregnant woman make a mad waddling dash for the facilities!!! Trust me, I saw myself. DH was gracious enough to tape me doing it while I was 8 months pregnant!
I wore sneakers on the first day and my feet were so hot and swollen. I did much better with flip flops the rest of the time.
I rode the safari. It was fine. I did ask to ride in the front. I am a little more concerned about bringing my little one this year now that she is out of the protective confines of my belly. I will just be holding on real tight!
Lastly, be careful getting on and off the attractions that move constantly when lading/unloading. My balance was a little off and I hurt my bum one time, plopping a little too hard in the seat. Thank goodness for all the padding I have back there

. I would hold my hand out for the CM to help me, and they all obliged. DH had his hands full helping DD's!!
Have fun!!!!