I've never tried bar ends but I'm always amazed when people say it is easier than shifting STIs... how is that possible? I understand if it's more reliable and cheaper but easier to shift when you have to reach? I don't get it.
I progressed from down tube to bar ends, and when I bought a tandem with STI, the bar ends felt pretty archaic. I had to upgrade my single to match the convenience and there's been no looking back. I guess everyone has their own preferences and I can't knock them, but it's STI for me.