I do customer-facing sessions too (focusing on Azure and OSS stacks) and quite enjoy the stunned silence when I pop open an SSH session and use it for a demo in their Linux distro of choice ;)
Most people don't realize how things have changed/are changing on a daily basis.
Yep. Last month I was in Moscow for a conference keynote and a workshop. Running through demos the morning before, I spilled coffee on my Lenovo and fried some keys on the keyboard. Thought a bit, pulled out my MacBook Air, and had everything running in time for a keynote rehearsal that evening. Nice stress test of the cross-platform mindset, not quite as nice of a stress test for me though.
Most people don't realize how things have changed/are changing on a daily basis.