Spiral, for way too long! People will always disagree about the leather. But having seen it all, I think the 2004 and spring/summer 2005 ended the best leather, or my favorite leather in general. But even then, there were variations as to color and leather quality. Teal is a good example. It was a great color, but some of the bags looked duller and flatter in color than others. But they used to be mostly good. And despite what I've said about the demise of my favorite leather, I have a Magenta bag from later in 2005 that is unbelievable. I'm sure I'm not the only one with that kind of experience.
There was a very noticeable change as production ramped up to meet demand. We got the shiny, thin leather, the extreme veining. Some people prefer it, but if you loved the bags before, 2006 was probably your least favorite leather. You couldn't count on it with any consistency - it was bag by bag. I think there are some good colors every season, but they do seem to be repeating very basic colors, with little variation.
Again, color is a preference, but 2004 seemed to me to be a banner year. 2005 had fantastic blues. I really like vert d'eau, grass green and french blue, but they are not for everybody. Maybe there hasn't been a color that tons of people go crazy for (like eggplant?) in a while. But that's just me.