We gave up on it for the same reason. It is absurd for a simple web analytics app to require massively more powerful hardware than our actual app does. And since it is a mysql mess, any updates that touch the schema put your stats offline for hours. I really can't fathom how using mysql is still considered acceptable in 2013.
I completely agree with the statement. I love Piwik and we use to monitor a lot of our sites. But I hate the fact that it's LAMP. Archive script runs out of memory at least once a week.
We run Piwik on 40M page views per month on dedicated server. Archiving data takes a few hours, but the UI is fast and it works. We used tips in: http://piwik.org/docs/optimize/how-to/
