Notwithstanding the absence of the top 5 riders of last year's Tour de France, the level of this year's edition of La Grande Boucle was up to the tradition of the event.
High speed averages in most of the stages, long hilly time trials done at 50 km/h by the best riders, remarkable VAM performances on the climbs.

The climbing time of Landis e Kloden on Alpe d' Huez (38'34") is only 30" slower than Armstrong's in 2001 (38'01").
It is true that Lance did almost the whole ascent alone, after having attacked in the first km of the climb, and that his violent acceleration in the first part compelled him to slow down in the final kms, where Ullrich was able to regain about 20 seconds on him, but Landis didn't give the impression to be forcing up at his maximum this year.

Getting back to Floyd's performance in the stage of Morzine, apart from the fact that in my opinion he was by far the strongest in this TdF, I think a determining helping factor was the possibility to keep pouring water on his body during the climbs. 
Being on a solo breakaway, with the team car regularly hading him fluids, Landis was able to keep his body and skin temperature lower, therefore to direct more blood (and oxygen) to the muscles busy in the effort.

The group of chasers were not able to organize such "cooling" strategy and their performances felt the effects of this, especially on the last climb, where nobody but Carlos Sastre was faster than Landis.