You won't regret the move to Resolve! Fusion is also a great alternative to AE once you get used to the node based workflow. Adobe is a complete rip off, especially for us Aussies.
5" Video Assist owner here. If colour accuracy is important to you I would not recommend the Video Assist. The VA has a known green tint issue. Blackmagic recently released a firmware update which claimed to have improved this, but I haven't seen any major improvements in the colour accuracy of my VA. Other than that it's a pretty good monitor/recorder with some great features, but the green tint is really quite annoying.
As someone who owns a Blackmagic Video Assist, I would advise you not to buy one. The green tint is very noticeable, I have only used my Video Assist a handful of times because the tint is so distracting. Blackmagic is well aware of the issue, but so far they have not bothered to attempt a fix for it. Now that the 7 inch model has come out, it seems as though they don't really care about the 5 inch model anymore. I am currently in the process of arranging a refund for my Video Assist, when that happens I plan to buy a Ninja Blade. From what I understand, the Ninja Blade has a higher quality IPS screen and you should hardly notice any difference between 720p and 1080p at 5 inches. Atomos customer service is 10 times that of Blackmagic. Blackmagic has a bit of a reputation for poor quality control and problems, especially with their cameras, as you mentioned. Before I bought the Video Assist I thought; surely BM can't stuff up a monitor... I was wrong. I never would have bought the Video Assist if I'd known about the green tint beforehand.