I do like all the new content, makes oceans a lot less boring. Tridents, especially with the new enchantments, are a lot of fun to play with.
I have mixed feelings about the command changes, but I suppose it was necessary. Although I don't like the name changes for the textures, I find it far less organised.
Is anybody else having trouble with resource packs? With default, the game already seems to run a bit worse than 1.12 for me, but when I use a resource pack, it causes lag so bad it makes the game unplayable... I don't exactly have the best computer, but it worked fine before, never had any problems, now.... 2 fps?
I think it really depends on the computer your using. I've been using 1.13 versions of certain packs and for me, anything 64x or below works fine for me with almost no lag (I'm currently using PureBDCraft and almost all of its add ons.). Its only when I use any pack that is 128x or the 3D blocks add on pack for PureBDCraft that I get a lot of lag.