The table clearly shows that BBM is different in terms of Security. It starts with the unique email-password combination and then gives a unique pin like a unique user ID. Except the PIN is unique to the device too. But the question here is: Do you need this?
If you are constantly bugged by people having your numbers, then you can switch to BBM which allows only those people to send you a message, whose request you’ve accepted. But then, this people can bug you by other means too. Most people like to publicly declare their BBM Pin. Well, in that case you will be bugged by people’s requests, anyways. It’s better on WhatsApp or hike, where you can block this contacts without them knowing about it.
BBM can help you when you want to IM with a person but don’t wanna give your number. We all have various friends whom you just IM and not talk. But, for most of such instances, I am happy to give my number otherwise you always have Facebook or also Google Hangouts, if you want.
hike is the only one to offer a unified SMS/IM coversation thread. Other IMs offer a SMS support but in hike, the conversation threads are merged into one. If you live in India, this threads also combine the free SMS that you can send via hike over the Internet.