Originally Posted by
veganeric
IIRC, he tried to make a cross chain front shift under power. That's asking for trouble with any mechanical system.
One of 7900's targets is to allow you to use all 20 gears, and trim-free, too. Cross-chain all you want.
If Red shifts good and is half a pound lighter it would seem to be better?
According to
this table, the difference between 7900 and Red is 183 grams, unless you have BB30. About one ounce of that would be the Red Powerdome cassette, which actually is pretty innovative. 7900's crankset is from an entirely different technological planet than Red, however... no need for special, heavier, stiffer "sprinter's chainrings" on Dura-Ace, they come standard
And from the chart, you'll notice DA's crank is lighter than Red, too.
Working at the LBS, I can also testify to Shimano's warranty department. All I have to do is pick up the phone and tell them "yeah, this customer's right-hand DA lever buzzes on rough chipseal," and they will not only send out a replacement that day, they'll replace both of them to make sure. Including new cables. Just on my word.
The last time we tried warrantying a SRAM shifter, they acted like they were doing us a big favor. "Send it in, and we'll fix it and send it back." And they did... after about three weeks. Good thing we had a spare lever to lend to the customer in the meanwhile.