That would be fantastic on a 4K monitor, with the capability of zooming into the paintings and the original audioguide sound. And the soundscape please. And the ability to customize the sound of my own footsteps. I would absolutely enjoy that.

Some museums have amazing architecture and feel (The Foundation of Joan Miro in Barcelona is a great example) and having that feel represented by a proper walkable 3D environment would greatly enhance the experience.

I'm a bit concerned though that simulated museum visitors may break the immersion -- we haven't crossed the Uncanny Valley yet.