Bar end shifters are very good shifters. They are more consistent shifting for beginners. I love my STI levers , Ergo Levers and my Double tap levers (don't know anything about Nashbar duel purpose levers and whatever else is out on the market). No professonal or serious racer would use bar end shifters. Not that bar end shifters aren't cool . Duel purpose shifters allow people to stay in a more comfortable yet aggressive riding position and still shift and brake. But there was a time when bar end shifters was high tech and several pro racers used them. I have one of my road bikes working very well with Shimano 10 speed bar end shifters , DA r/d and with wing style shallow bars the bike is a blast to ride. I also use some inexpensive Tektro aero brake levers and between the Tektro levers and the DA bar end shifters I might have saved some weight but I know I saved a bunch of money.