Originally Posted by
MinnMan
Interesting. you start out looking for something "objective" but before we get to the end, we find it's about what interests you. So I guess when you write "objective", you mean the opposite, "subjective".
(Some other guy on this thread would pull out his fancy "reducto ad absurdum" and tell you that you would care about weight if the difference were a million pounds, thereby concluding that you were not telling the truth about caring about weight. But that indeed would be absurd. The small difference in weight between DA and Ultegra doesn't matter to you. I have no interest in convincing you otherwise)
I have no idea what subjective benefits DA has that might interest you, so.I won't try.
Speaking personally and without regard for whether or not this impresses you or anybody else, I would simply point out that I was not buying a groupset, but rather a bike that came with a groupset. So the bike that came with DA had many other features that I sought, and in addition I was happy to be getting the the drive train that was light weight and had DI2 (available also with Ultegra, but not 105). The price differential between the DA bike with additional components that I wanted and the bikes with other groupsets and different sets of those other components was within a range that was not consequential to my decision.
I own 2 bikes with different vintage DA drive trains. I own 3 bikes with different vintage 105 drive trains (well, one of those is GRX 600, but that's approximately 105 level). I'm mostly happy with them all except for the oldest 105, which I think is 5600, and doesn't shift nearly as smoothly as, say, the mid-aged 105, which is 5800 and really pretty great. But the 5800 doesn't shift as smoothly as the 9150. Well, of course not, it's not electronic.
The DA bikes are much lighter than the others - both around 15 lbs. The specific weight of the drive trains isn't really how I think of it, but rather, it's the overall weight of the bikes. To make a light bike, you need to shave a little here, a little there. Each individual choice (this wheel vs. that wheel, this drive train vs. that) is small, but the accrued difference is larger.
Well you only had to read post #1 to see that I was looking for any objective advantages excluding weight, which I already know all about.
Now you've bothered to explain how you ended up with DA on your bike, rather than leave it to my imagination, it actually makes a lot of sense. I would probably have done the same if buying a complete off-the-peg bike.
Di2 would have pushed me to at least Ultegra level Shimano for the reasons you mentioned. Current bike has 105 7000, which is really hard to fault after 16,000 km with no adjustment required. But would like to try electronic Shimano (but won't be on this particular bike now)
I also agree how incremental weight can all add up. I'm aiming for an approx. 16 lb overall build, but it's not critical and won't affect my groupset choice in this case.