Depends on how are you using your phone and what applications you are running. Try to use G-maps and facebook for a couple of hours and your battery will be empty.
Like I say in the article - mileage will vary depending on usage, and GPS still sucks the battery. However, 4 days on normal usage is a nice achievement :)
Are you using TaskKiller? I use it to monitor "suspicious" services on my Adnroid. That helped me to disable many "old" apps that just run-out my battery.
I used to use TaskKiller for memory clearing purposes. Haven't used it since I upgraded to CM 10
I am working on data sync service, mainly sync data between cloud and mobile. 30% of apps installed on my Android do data sync. This thing is killing battery.