I am in the process of finishing my MM. I went with 3/16" thick Mirror Pane Glass vs the Acrylic for a couple of reasons.

1. To support a small local business
2. No chance of waviness in the glass.

Yes, it is substantially heavier and brings about a spectacular boom when dropped vs. Acrylic.

My next project which will be a laptop screen will use acrylic because of the costs associated with using glass.