Agreed. 99.97% uptime for May is excellent. I've worked with a lot of enterprise systems (to include military!) and we would love to have that high % of uptime.
Somehow Heroku doesn't seem that great to me.
(And that comes with excellent support - for example, I asked if they were planning to offer Python and they said "Sure, just gives us a couple of days to set up a machine with Python for you", even when I was only interested in the cheapest plan).
I know they don't serve the same market, but I find it strange that a service that costs an order of magnitude more doesn't have a better uptime than cheap shared hosting.