It's definitely worse than it was with iOS 10, but since I use a Smart Battery Case my iPhone still easily lasts a full day, instead of the usual two. But like jsook724 says, it's a beta, a non-complete iOS update. And not to mention that with big updates, people (including myself) tend to try out every feature causing battery life to drop more significantly. I already see a difference today compared to yesterday for example, since I've been using it more like I did before I installed iOS 11 beta 1. Like, more realistically you know? And of course Spotlight does a lot of indexing after updating, that'll account for a slight difference as well.