The Pugsley frame is offset 17.5mm towards the driveside. This means that both front and rear wheels are dished 17.5mm, so "standard" hubs can be used and the frame has been tweaked accordingly. The wheels are still in the centerline of the frame and it rides totally normal, but the driveside dropout on the front and rear is 17.5mm further out that you're used to. The big benefit is the ability to swap front/rear wheels if need be, and hub cost. There is no chain rub in any gear, with most tires. I had the 4.8" Big Fat Larry's on mine (65mm rims) and didn't have rub.
The Mukluk's are nice, but handle completely different. The Mukluks are more upright like a hybrid, whereas a Pugsley is full mountain bike geometry and rides like it. The 2013 Mukluks have alternator drop-outs if you want to run singlespeed, but no one makes a 170mm IGH yet, so that's still not an option. The 2012 Mukluks had chain rub in stock form, and drivetrain mods were necessary to fix it. Supposedly this isn't an issue with the 2013s, but I haven't seen one yet.
I'd also look at the 9zero7 and Fatbike bikes as well. I still like steel though, and a can of Frame Saver is all it takes to nullify the corrosion issues.