I recently took a three day trip with the newest incarnation of the Patagonia MLC. Got it mid-May, came just in time to pack for my flight the next morning. Didn't even have time to play around with it before my trip, just pulled it out of the UPS box and loaded it.
I'm used to flying with an Arc'teryx Blade 21 bag, which is small compared to this, but I love that backpack and it swallows an amazing amount of gear and is a compartmentalized sideloader. I'm obviously pushing the onebagger concept, but I did six days in Germany/Prague with just that little Arc... But I knew that was beyond pushing it, and so ponied up for a "big bag".
I downselected the MLC instead of the Arc'teryx Covert (no real organization, just one big compartment) and an Osprey Ozone 46 (tons of organization, bordering on gimmicky -- but I did like this a lot, but I wanted a full-zip open / book style packing method). The Osprey has a really good support system with true "backpack" straps and belts. Lots of room, but if I ever wanted to bring a suitcoat or boots, it would have been wrinkle-city and crowded quickly.
So I went with the MLC because it looks like it had a good mix of "giant main compartment" and "some organization without getting too silly and overspecialized".
My impressions: The MLC is a little "shapeless" - I might have preferred a little rigidity to have it hold its form (maybe a lightweight partial thin hard foam or plastic framesheet that holds up the sides), but it's a good mix of organization / separation / and capacity.
I haven't yet gotten the hang of how to pack it - there's a side panel with laptop padding, perfect for the laptop I don't ever seem to bring with me.
Seriously, it's actually nice to have a plain, only slightly padded pocket - even if I don't laptop, I can put dirty clothes in there separate from the clean stuff, or use it for another packing compartment for toiletry bag, etc.
There's some zippered and mesh-viewable pockets inside (socks, rolled underwear, etc.), and a huge main compartment. I wound up putting my boots in the main, one each top and bottom and it actually gave the bag some form and shape so it didn't hang so sloppy. If I only had a small amount of gear in the bag, it would probably be kinda... baggy and slouch. But, I bought this for times I *am* overpacking, I can use the Arc' for trips when I don't need as much gear. I sometimes bring a helmet and boots and the Arc' was a no-go for those kind of non-compressible items. This one easily packed four changes of casual clothing (tees, base layers, jeans and pants, sportcoat, couple shirts) and I didn't even touch two of the extra pockets.
The other side pocket has organization for pens, electronics, etc. Seemed a bit hard to get to, but I'm chalking that up to the fact I haven't gotten into a regular routine with the bag yet, where I prefer to stash X or Y and know where to go for it. But there's a divider that has maybe five or six compartments that I'd slide in chargers, tablet, sunglasses, wallet, passport, etc.
The durability I suspect will be no problem - this is good grade material. The backpack straps, while the "hideaway" style, actually felt quite supportive and comfortable. I didn't bother with the included shoulder strap and took it off: If I'm walking far, I'll backpack it. If it's a short walk, I'll sling one backpack strap over my shoulder or carry it by the briefcase handle. Don't need a sling flapping around. It's nice to have the option though for those that like this.
I wound up putting a carabiner on one of the exterior loops, using that for water bottles or hats that I might want fast access to.
Zippers were a little sticky, but look to be of durable quality.
I'm going to take this on a few trips this summer, see how it grows on me. I like it so far and know it's going to prove handy on longer trips. I pack really light and do not like rolly bags in Europe or places where I know I'll be doing a lot of walking. If I'm on a trip where I may need six or more changes of clothing, possibly a suitcoat or extra shoes, or specialized, larger gear like a helmet or tripod and camera/spotting scope - this bag is the answer for that preference.
TDM