I've had a good time working with Blue Box Group (https://bluebox.net/). I've been using them as a backup for an uptime-critical festival application that runs on Heroku.

They helped me by setting up a Capistrano script for me that I run alongside my Heroku pushes. They set up the entire stack according to a specification I talked them through. And they helped me write a script to keep my backup DB in line with my production DB (Heroku Postgres). It's not nearly as quick as provisioning a Heroku app yourself, but if you can spare the week it took to get all that put together with just a little hands-on work, it's not bad.

Overall good experience, good support, if a little slow to respond, but I think mainly because they had one engineer working my case for the entire process, who I'm sure was also working with other customers. But having that 1:1 relationship is good, too. Tradeoffs.