I built a bike from used parts a year ago and did a lot of frame research... The gist is that each manufacturer has two or three levels of carbon they use on their frames. In theory, the higher the level, the better the bike. That changes less year-over-year. So, the actual carbon on a 2011 S-Works may not be appreciably different from the carbon on a 2017 S-Works. The other key variable is that bike generations have major design milestones that may be significantly better. But there may be key generations that are very good and the current models are not appreciably better. For example, IMHO the SL4 S-Works Tarmac is a peak, and the newer SL5 and SL6 generations are not massively better than the SL4. You have to research the generations yourself and make the determination of when a generation reaches a threshold that is good to you.

So, to answer you test question... the 2011 Tarmac is the SL3 generation. I am not a fan. It has a funky seat post bolt and other quirks. I would pick a 2016 Elite over that one. However, a 2012 Tarmac is an SL4, and I would choose a 2012 S-Works every time over a 2016 Elite with its lower grade of carbon.

Thanks for your message. I agree I have to take into consideration the generation for each model, that's probably the key.