I use both orkut and facebook, but I like facebook more than orkut because:
1. Orkut allows special characters in FName and LName, so it is very tough to know who is the person in your friend list. This is not possible in facebook.
2. Orkut has the OpenSocial applications like Facebook, but its less, you can't autoupdate your status in Orkut using status from twitter or something else, its there in facebook.
3. Orkut has weird groups, even Facebook has them as Fan pages but lesser I think. At least it doesn't come in normal searches.