Is the uptime satisfactory? It's worrying that Heroku's Standard production databases at $50 or more a month have "up to one hour of downtime per month" (https://heroku.com/pricing)

How about support? The standard free support mentions "1+ day response times", which sounds a lot worse than what e.g. Linode offers.

Are page speeds okay?

Do you have personal experience with high-traffic sites running on Heroku? The reason I ask is that I seem to recall someone mentioning here on HN in an earlier discussion that Heroku is alright for smaller sites, but not for high-traffic ones.

Does Heroku offer any value for people who know how to set up servers but are inexperienced with larger setups / load-balancing?