I have the A2A B-17 with AccuSim and an HTC Vive, and can report on what works and what doesn't (I am using the Vive Controller).
The aircraft looks great, everything that should be visible from the windows, is in fact visible, and the little extras such as vibrating engine cowls and windows that can fog up do come through in VR very nicely. You can watch from your window as the front gear slowly drops. The cockpit is high detail and has 3D gauges. The cockpit night lighting is beautiful and the large gauges make reading them easier than the average aircraft. The scale of the aircraft and cockpit seems to be perfect. There is both a Captain and a Copilot VR seating position.
It is possible to fly the aircraft entirely in VR. It is not possible to start the aircraft from Cold & Dark using only the Vive Controller. A mouse is required for a few steps. However, you can stay entirely in VR while doing this.
If you just want to simply fly, and let the copilot take care of your engines, then you will be fine in VR. If you want to start the engines in VR as well, that can be done with a bit of difficulty. If you want to take care of the engines yourself while in flight, or use navigation devices, then that will require more than a little extra patience.
I am using FlyInside v1.62 (HTC Vive version).
RM - edited out the known issues because I noticed the forum "no bugs" request after writing this post.