#1 - is tehe grind and blade size the same for all three? I find that some grinds take more care than others, 1/4 hollow being pretty forgiving for me, and full hoollow requiring more attention to prevent skipping. So if the Le Grelot is a full hollow, and the other 2 are not, that could be part of the issue. Could also be a size factor. Is the newest blade smaller or larger (5/8 vs 6/8 or 7/8?) The change in size may require a slightly different technique.
#2 - could very well be that the different edges came from different honemeisters, and that one may be smoother than another.
For an example, I find my 5/8 1/2-hollow Boker to be a slighter harsher shave than my generic 3/4-hollow 6/8 blade. And my 1/4 hollow 5/8 W&B to be the smoothest of the bunch that I have so far.
http://badgerandblade.com/vb/group.php?groupid=81 - Washington State Wetshavers - because we're all wet here anyway.