It terms of handfeel, I think swift leather wins hands down because it's so smooth and luxurious to the touch. But this means that it's a lot more sloppy in a birkin and if you want a relaxed Birkin look, this is it for you. It gives massive batwings and like gazoo says, the area around the handles looks very strained, only because the leather around the handles slumps when the birkin is being carried. Over time, both Clemence and Swift slumps into a heap.
(That said, I saw pictures of a few-year-old 35cm Clemence Birkins recently and it sits up real pretty. So my guess is that Clemence these days are softer and thinner than it used to be. This rings a bell because when I first received my JPG Shoulder Birkin from my store, the SA did tell me that the shoulder birkins used to be alot heavier, and my guess is that Clemence was indeed thicker and therefore heavier in the past)
The only piece of swift I have is in the Lindy. And it's very soft and slouchy. I have been using my Lindy very casually, and take the least care with it. So far, no scratches. But there are streaks of dirt marks around the folds of the leather. I hadn't noticed until my craftsman straighten the leather on my Lindy to inspect the bag. So, the leather does trap dirt more than, say, Togo or Clemence for comparison.
I'm especially interested in Birkins.
