I like the crispness of down tube shifters, and I like the way very little of the cable run requires housing. I think index barends work better for anything over 6 cogs.

I think the Ultegra indexed 8-speed barcons, available for as litte as $56 including cables, housing, and cable guides, are a tremendous bargain. The Rivendell pods are also great, if you already have compatible shift levers.

If you are upgrading a bike that came with stem-shifters, the built-in downtown cable guides on many stem-shifter equipped bikes are bar-con ready.