Due to recent outages, I've set up a Bitstamp uptime monitor here:
http://stats.pingdom.com/vbxa0yliwzy1/823007It will give us a better idea of how reliable the service is and how often it is down.
You can also subscribe to UP/DOWN alerts here:
https://twitter.com/BitstampMonitorI hope you'll find it useful.
I'm in no way saying that Bitstamp is not a good service, in fact I find it one of the most reliable exchanges. It's just nice to have an overview.