I managed to get my main to 120 a week ago today. In general, I've found the leveling process in Battle for Azeroth so far to be totally enjoyable. The stories are engaging and the zones are well thought out. There are plenty of side quests to add flavor and keep things interesting and also provide the opportunity to mix up the leveling paths a bit.
My total time to 120 for Joar, who is almost always my first toon out of the gate, was 20 hours and 27 minutes. Note that for my first toon, I'm always reading all the quest text, and exploring and so it is never an attempt at a fast pace to max level. That being said, this was my fastest time for the first toon leveling since I've been tracking it, which started with Cataclysm. My previous shortest had actually been Warlords of Draenor which clocked in at 24 hours and 30 minutes. The longest was actually Cataclysm which I started with my paladin on and took a whopping 35 hours (which may explain why I've never started with the paladin again!)
I've managed to unlock world quests, finish up the Quest and Explorer achievement for both zones and am grinding out daily emissaries to keep unlocking portions of the War Campaign and the remaining Pathfinder achievements. Gearing up has been relatively slow, just like it always is at the start of an expansion. I'm geared enough for heroics now, so that should help, although I'm only doing one or two a day.
I wish there were more...or any, really...weapons available from world quests because that would definitely help my gearing process.
For my second toon, I decided to break with tradition and go with one of my alliance toons, so my Night Elf Hunter has started the journey through Drustvar. I want to maintain some momentum on the Horde side so I think what I'm going to do is finish one zone on the Alliance hunter, then do one on the Horde hunter...etc etc until all three are done.
My plan will continue to be to focus on gearing and world quests on the main 5 Horde toons - warlock hunter, death knight, paladin and druid.
I've also started working on professions on Joar, although not making much progress there. I've gotten a few points out of the way in both enchanting and tailoring, although I have a long ways to go on both. It looks like there are a decent number of recipes locked behind reputation, so that'll hold those up a bit.