One area is we're focused more on delivering more guidance and expertise around what you're doing with your database, in addition to ensuring your database is healthy and running. An example of this is notifications that we deliver around unused indexes, where you may benefit from other indexes, or other places where you can quickly optimize your DB. This starts to free up a DBA to add higher value tasks or for smaller shops lets you get by longer without a need for a DBA.
Another big area is features we deliver on top of Postgres. This ranges from followers which all you to easily scale read traffic, or allow for your database to be replicated across not just AZs but also regions. There's the other spectrum of this as well including dataclips. Dataclips make it easy to share data in a simple way, as well as build richer dashboards by integrating with google docs, or quickly prototyping APIs.
If you're curious on various technical details we'll be documenting that soon but would be happy to correspond via email, craig at heroku.com
I understand that "forks" and "follows" are easy concepts, stats are cools, etc. but I personally wouldn't want to pay double or triple for that (and I'm not a DBA, so I feel the pain). Not that my word counts much as I'm on the smallest Heroku production plan, so I guess my bill isn't exactly interesting for this kind of discussion. In my case, I would say that even saving $25 off $50 can be offset by these additional niceties. But, I don't know what I would think if I were a customer paying $1000/mo.
I just switched off heroku after using it for a couple years(sorry! I wish I could have stayed). I will attest dataclips are really cool, but your guy's pricing is out of wack (and customer support is eh).
Heroku's solution is 2 to 4 times more expensive for the same type of DB, and RDS even allows for reserved instances to further lower the bill.