I have a twiggy from the A/W 2005 season and I just received an '04 twiggy that I purchased from someone. My first b-bag was a chocolate city (which I sold for the '04 bag). When I got the '04 bag, I was stunned at how different the leather felt from '05. I mean I had heard about the difference from other posters but actually feeling it... I really don't understand how the leather has changed so drastically. I complained to Bal-NY last week about it. I asked an SA why the difference in leather in a span of a year... initially she claimed it was probably because 2004 used different leather but hello, the authenticity cards had always said "chevre". She put me on hold for a minute to "double check" and came back and said actually they were the same leather but didn't provide an explanation for the difference.
In terms of durability, the 04 bag I've got is used but the wear is minimal. So in terms of the condition I got it in, it seems to have held up pretty well. On the other hand, my 2005 twiggy is a calcaire and it came with really really nice leather compared to some of the other colors. It isn't quite like the '04 leather but comes the closest. It has held up extremely well and hasn't gotten dirty as many fear and I've used it at least 10 times. I used the chocolate city quite a bit too when I had it and it held up very well.
I would definitely buy with caution. Over the weekend, I bought an ink city from NM and the leather was terrible... it was even thinner than the A/W '05 bags. I wasn't in a position to "pick and choose" a bag with a better leather because all their stock was divied up for others who already waitlisted for them. I returned it for a refund after toting it around for an hour while I did more shoping. Just make sure wherever you get your bag that they have a good return/exchange policy and make it clear to the SA your preference for leather. I've become ultra picky now that I know what 2004 leather feels and looks like. I really don't like the whitish veins and marbling and the thin-ness.
Phew! Sorry for being so long-winded! :shame:
ush: 
I didn't know this leather was cheaper to make than the others, that would explain a lot. Arrr, for a 1K+ bag, they should really think about their customers wishes rather than the bottom line :cry:
