Well if you still have faith in Cancellara's 2010 attacks in Roubaix and Flanders, you must be viewing from a very naïve and/or uncritical perspective.
I used to have a lot of time and respect for him, but that evaporated with those two comically effortless yet ridiculously devastating attacks. I know plenty about interval training, thanks - done loads of it. And I know that it doesn't confer such out-of-character short-lived (i.e. two races only) supreme demolition capability. You'll note that Cancellara never exhibited that same capability before or after those two races; yes, he could ride away from others in convincing fashion, but never in such an effortlessly smooth and gliding but simultaneously ultra-effective way. And in those two attacks, he rides like he's on rails despite putting out enormous wattage, in a style that is highly reminiscent of riding with the smoothing consistent (throughout the pedal stroke) input of an assisting motor - which was the reason for posting an update of my 2010 critique, now made with the benefit of knowing exactly how such motors affect pedalling and riding style; and if you examine those attacks from a more analytical viewpoint, you'll see his style (not to mention the outcomes) there reeks of the effects of motor-assist, especially when you compare with his usual style and body/bike movements while attacking.
As I wrote in 2010: that acceleration, and similarly the one in Flanders, is just unnatural. No rider is strong enough to make such incredible progress over other riders already going that fast without getting out of the saddle and sprinting - he is that fast. The other riders weren't exactly dawdling, as you can see they were already moving away from the rest of their group who did seem to have let up slightly. Not only does he rocket away without getting out of the saddle, there is literally NO perceivable increase in effort from him - not even a slight extra crouch or tightened grip on the bars or adjustment of pedalling action or extra tensing of leg muscles; it is utterly effortless compared to what he is already doing AND he turns it on instantaneously AND he's able to turn round to see the reaction in the middle of doing this incredible acceleration.
Moreover, the fact these attacks coincided with all sorts of bizarre hand-lever-bar hi-jinks (again, not seen before or after, as far as I know) is also nicely (in)convenient.
If you can find evidence of him replicating the gliding-on-rails manner and high-wattage smooth-but-devastating effortlessness of those 2010 Roubaix and Flanders attacks, let's see it.