It also depends on the sort of touring you want to do. I have a few of the bikes discussed, so I'll offer a comparison.
I have the following:
2006 IRO Rob Roy 60cm (no longer have it... it was too big)
2006 Redline 925 54cm (58tt)
2008 Jamis Sputnik 57cm (57tt)
2008 On One Pomino Large (54st, 55tt)
2009 Surly Travelers Check 58cm (58tt)
They'd all be fine for some kind of touring.
The Sputnik is the lightest, fastest, and has road racing geometry. It still feels pretty fast with 5-10lbs of gear hanging off the seatpost. The frame is pretty stiff, so low pressure tires are mandatory for comfort. I use 28mm tires around 70-80psi. Mine has no braze-ons for racks or fenders (but the newer models have fender eyelets).
The 925 is next fastest (unloaded) and has road sport geometry. It has braze-ons for a rear rack and fenders, and can fit 30mm tires under the fenders. It's my bike of choice for brevets and commuting. It handles well with a loaded rack, but the chainstays are only 42cm, so you might have heal clearance issues with large panniers. It would be best suited with an extra large seatbag and perhaps a small handlebar bag. It only has single-eyelet rear dropouts.
The Cross Check or Travelers Check can fit wider tires thanks to its cantilever brakes. It's pretty comfortable unloaded with skinny tires, or you can load it up and increase your tire size to match the load. It's practical cargo capacity is the same as the 925's.
The Rob Roy is basically a Cross Check with track fork ends instead of forward-facing horizontal dropouts. Mine was too big, so I didn't ride it much before selling it. It seemed like it would be pretty comfortable if it fit.
The Pompino is the best frame for loaded touring. It's the only one of the bikes that I keep a rear rack on all the time. The chainstays are slightly longer (up to 44cm), which helps with heal clearance and stability. The head angle is steeper than the 925 or Cross Check, so it also handle a front load better. It's pretty stable with front panniers, rear panniers, or both. The frame feels slightly stiffer than the 925 or Cross Check, so I tend to be more particular about my tire pressure on this bike. It would be best paired with a Long Haul Trucker fork.
My Pompino is a little smaller than my other frames, so I'd be more inclined to take the Travelers Check or 925 on a long tour.