I wanted to upgrade from my 08' Tarmac and debated the new Tarmac or the Aethos for almost a year. I'm nearly 50, but still love fast race bikes, but i dont want my fillings to raddle out of my teeth. In the end, the Aethos reviews commonly state how fun the Aethos is, so I chose the Aethos and I am so glad I did. This is a very fast bike, it rolls with ease and loves it when you get out of the saddle, and bombs descents with rock-solid stability. The part that amazes me the most is how comfortable it is to ride. It eats road vibration, but doesn't feel disconnected or sluggish. How did they do that? I don't know, but I'm glad they did. I've only put about 300 miles of cold winter riding on this bike, but on every ride thus far, I've caught myself smiling and laughing at each new revelation about the Aethos. It is fast, comfortable and fun. Plain and simple. I got the entry level Aethos Comp - Shimano 105 Di2 and am very happy with the bike and components.