I took Miles by Motorcycle live on HipHopVM on December 15th.
I was concerned about crash problems since it's a long lived process so I set it up to be monitored by ?upstartd, which will restart the thing automatically if it crashes. However, it's been remarkably trouble free.
It simply works.
I was playing with Google's Webmaster tools a bit when I came across this interesting graphic showing crawler page download times for the last few months:
It's pretty obvious when the site was switched over to hhvm. :)
formVista generated this page in: 0.0918 seconds
using '6291456' bytes of memory