We were just there and used kingdom strollers. I had previously used them at WDW and was pleased. Only thing was that we had to meet them at bell services. They said they couldn't leave it because the hotels won't hold them., so they drop off/pick up at 8am and 5pm. But a lot of the stroller rental companies don't seem to deliver to universal at all. We weren't there when they dropped it off so bell services held it for a bit with no problem, and they held it again on our departure day because we had to leave early.