An update- it's been a little over a year.

I've used it on/off during this time to go to work.  In an office and not in the jungles of South America fishing for piranha by stuffing bits of raw meat in the bag.  The bag hasn't had to go through any feats of strength.  The worst abuse it's gone through were a few rain showers.  It's a spoiled bag, I guess.

Overall, the bag is tough and still looks good.  The leather has softened up a bit more but still is fairly firm and rigid.  The leather is as durable as what the website says- but the metal bits not so much- I usually sling the bag a la messenger bag style or just carry it like a briefcase.  From the pictures you can see where the metal has been wearing down which is concerning because I bought this to last a lifetime.  I have no concerns about the leather.

I'm glad I got this- it's OK if it gets scratched up and I don't really care if it is raining or snowing or whatever.  This bag has a cowboy business look to it.  It's casual but still appropriate for work.  I've never used the bag in the backpack mode- I think it just looks silly like that.  In terms of color, I've have no regrets- the black and dark coffee brown were too dark.  I was torn between the chestnut and tobacco but in the end, the tobacco light brown works the best for me.  Size-wise, the medium is enough to hold a few folders of paper, a 13" Macbook Pro and random stuff in the front pocket.  But it will get heavy.  I don't think a bigger size would have been better for me either.

Usually I get bored of things quickly and start to look for something new- not with this bag.  I might eye a nice briefcase at the mall now and then, but that's about it.  Lately I feel like the leather is a bit dry and needs a bit of conditioning so I bought the Chamberlain's Leather Milk #1 that they recommend.