Looking for Advice/Info Re: Healing Classes in BFA

I was very much on the fence regarding BFA right up until about two hours ago when a friend convinced me to come back and play. I'm curious as to what healing classes are like now, being as I've literally made no effort to learn anything about this expansion.

I raided early in Legion as a resto sham and loved it, had dabbled a bit in pally healing and liked it too. In the past (Pandaria) I'd raided as a disc priest. I've never really done druid healing on a large scale, so I'm a little curious about that as well. Basically what I'm asking is what people think of healing in BFA, which classes have improved and which aren't as great as they could be.

Thanks for your input and time!