Which features of iPhone 4S are not working in India?

Which features of iPhone 4S are not working in India?

The Phone does not detect the SIM and I could not see any network.

It must have been locked with a CDMA carrier like verizon

The iPhone 4S is picky at accepting SIM cards, it prefers factory made microSIMs
It takes a lot of time to latch on to a network
3G coverage is not great in India and the iPhone 4S does not have a toggle switch to turn off 3G. Hence the device might be ideal for Indian networks
Apple is marketing the 4S as a World phone, but refuses to work on certain operators. Aren't they supposed to take responsibility for this issue.
Some users who are roaming internationally in India with a 4S might also faced this issue.
Users who faced this issue had purchased factory unlocked phones from Apple in UK, USA, Singapore, Canada and few other countries where Apple is selling factory unlocked phones.