I loved the bar-end shifters. I tried to use them to great effect in crits (I don't really do races with long hills). Since crits were my best event, I optimized the bike for racing on the drops. I lost a big advantage in sprints once STI came out. Incidentally I only used the right one - in crits you barely touch the front shifter. So I've accumulated a pile of NOS left bar end shifters and right downtube shifters.

One of my teammates was a bar-end connoisseur and did some modifications to make things work better. I followed most of his steps.

1. Cut down bar so your hand, when in sprinting position, is on top of the bar-end. Really the meat of the palm of your hand is on the shifter and hangs a little behind it. For me, this meant cutting the bar just into the curve of the (non-ergo) drops. Regarding hitting bars with knees, I still do that if I don't cut about 3 cm off the bar (I just did this on the bar I have on my bike now).
2. Remount the shifter backwards on the "handlebar plug". This way the shifter is much more forward. Involved some home-made machining. This was necessary on the terrible Shimano mounts. For Suntour, not necessary.
3. Remove any rubber shift cover (if applicable). They simply numb the shift feel. Drill holes in the Shimano shifter for wet weather traction.
4. For optimal shift performance, let the cable stick straight forward and loop back to the downtube. For "clean" looks, run it along the bar. I used to drill my bar just in front of the lever and next to the stem and ran the cable internally. This was before these superlight bars. I never had a problem with breaking bars but I don't think it would be a good idea now.

With real drops, i.e. not ergo schmergo bars, you can hold the bars firmly enough to sprint at 100%, shift a bar end (or Ergo or STI), and brake if necessary. I still use the same hand/bar position except I now use Ergo levers. Bigdraft is right - although bar ends are great from the drops, the current brake/shift levers allow you to shift from the hoods as well. Plus with indexed shifting, you don't have to learn or think of how to shift, just bang bang bang and you're gone.

Probably the best known US racer to use this setup was Leonard "Harvey" Nitz.

blast from the past
cdr

ps on a straight block one of the cool things you could do was use a large flange rear hub and change spokes without taking off the freewheel. You knew a freewheel was tiny when you could see the spoke heads behind the teeth of the largest cog.