Had initially went with this setup thinking it would be a good setup around here and the idea intrigued me. So before I order the parts necessary to do this I read up on it on surly's website. They it was explained that if you had kept it with a two tooth difference, you wouldn't have to change wheel position.* Also recommended the use of a 9 speed chain with the setup and to use their lockring for the added protection against stripping the hub(already was running a surly lockring) and chainring bolts for a double. OK, get the stuff ordered and once everything arrived went to install the parts crankset no problem at all, dingle cog threads on no problem at all. The problem was the surly lockring, thing was too thick for the setup and had so much overhang that I didn't trust it and put on a dura ace lockring instead, which fit the hub perfectly.
Advice to those who want to try this: get a tensioner if you're going to run this setup, it does make it easier on the road to get chain tensioned properly.
With that now out of the way, time to ride. Start out in the 46x17 gearing, stop a bit before the first big climb to change to the 44x19 setup. This is where the asterisk comes into play here, hub is not centered in the dropouts when the chain is tensioned perfectly. So besides the claim you don't have to change wheel position when you maintain the two tooth difference, you do have to change the wheel position.* Not that big of a deal, it has made it easier to climb, by all of 2 mph. Gives a good chainline and is silent.
Now that I've had a couple of months on this setup, now know to run a dry lube. Even with that you get to the second asterisk, your hands are going to get dirty even with the dry lube. Only way to avoid is to run it sans chain lube, which isn't good for the drivetrain. Also had the great pleasure of getting a small piece of debris lodged between the 17t and 19t in such a way that it wouldn't let the chain sit on the cog correctly. Plus the 9 speed is a bit unnerving on a fixed setting have a disliking of shimano connecting pins. That leaves you with the choice of permanently fixing the chain together, which isn't recommended on a modern chain or using a quicklink which the 9 speed type isn't overly confidence inspiring.
Overall, do I like the setup: It's just ok. Would I run a setup like this again: hell no. Would I recommend it to someone else: probably not, but feel free to try it if you want to.