Hi Neil,
I've got a 70D, but I'm just a novice asfrophotlgrapher - in fact if you've seen my thread In beginners astrophotography you'll realise how badly it can be done.
But here's my 2 cents worth- the liveview is excellent for focusing and the screen has a universal joint so there's no contorting yourself when viewing overhead. I've found it easy to use, with pretty intuitive menus, and the wifi is great for remote camera control. You can sit inside while capturing I images, set up the camera to take long sequences of long exposures. The remote software has an intervalometer. You just have to remember to disable wifi to shoot movies and when using USB to connect the camera to your. computer.
Sorry I can't help with the image quality details- that's still out of my league, but it's had good reviews elsewhere for astro and terrestrial.
Cheers
Luke