It's interesting — very few customers are actually bent out of shape about this. (A few are, for sure.) It's more non-customers who are watching from the sidelines that seem to be upset. I do want to try to explain ourselves to the community in general, and that's what this post was for. But my first loyalty is to serving our current customers well.
I'm using gunicorn with python, and if I use the sync worker the request queue easily hits 10 seconds and nothing works; if I switch to gevent or eventlet, new-relic tells me that redis is taking the same time stuck getting a value. This is using the same code in my current provider that works just fine with eventlet and scales well.
To add insult to injury, adding dynos actually degrades performance.
Can you email me at adam at heroku dot com and I'll connect you with one of our Python experts? I can't promise we'll solve it, but I'd like to take a look.
Would you be willing to pair up with one of our developers on your app's performance? If so email me (adam at heroku dot com).
Fwiw, I've found the addon / db connection limits to be the primary blocker when load testing so far.
Seems to me you don't get it. Sure there are some very vocal non-customers but you also have a lot of potential customers and users (spinning up free instances) evaluating your product and hoping for a better product. I agree that your true value is the abstraction you provide. Some of these potential customers want to ensure Heroku is as good an abstraction as promised to justify the cost and commitment.
I'd argue that we dropped the ball on that before (on web performance, at least), and are rectifying it now.