I am a happy user of Telegram but I don't think re-inventing ethereum with a small team of developers is a great idea. But then again, using existing tech gives you fewer opportunities for cash grabs...
I'm not clear on stellar.
Tinfoil in me says that bank created Ripple just to get easy Bitcoin.
I don't pretend it is secure and listening to HN I've been halfway expecting a huge flaw to show up but so far, -nothing.