I myself have updated to the latest iOS 11.4.1 beta version. And it seems to be working fine as a daily driver. Except for a few issues.
Download iOS 11.4.1 Beta 2 iPSW for iPad
Download the latest iOS 11.4.1 ipsw beta 2 files for ipad models, from the links below. And get it free for your iPad .Without UDID or Developer account.