I'm surprised there's really much alternative. My schools either used Moodle or Blackboard and Blackboard was absolutely awful since it was a product of just acquiring and suing companies out of competition.
But, it's one of the few LMSs designed post-Web 2.0 so things that require a refresh or reload in BB, etc., generally happen much more smoothly.
These days I like Brightspace (aka D2L) the best, but that could be just because the way I interact with it.
(I write LMS integrations for a living).