With the old S3 (fitted with a basic case), it had no idea if the case was open or closed. Set to Hands Free mode and with a headset in, the phone was completely useable tucked away in a pocket almost all the time.
OK - just got a Note 3 (got in quick when I heard rumours of a Note 4 about to launch) and I'm loving it. I upgraded from a Galaxy S3 and the extra screen size is wonderful. I've also fitted an S-View case which is very convenient, but I have a grumble about the way in which it interacts with S Voice. I tend to keep my phone in my pocket and use it via a headset (wired or Bluetooth) most of the time - this is particularly relevant with the Note which is such a large lump that it can be difficult to get out of a pocket quickly! The trouble is that when I call out "Hi Galaxy", it pops up a message in the S-View window telling me to open the case! Any one know how to set it (possibly patch) to work with the case closed?