Think this has been covered, yes Cross bike is more aggressive geometry. What was interesting to us on Surly - The DH's city bike is the Surly cross check in a 58cm and fits great but he would actually go to a 56cm if he bought the Surly Straggler - again geometry.
Touring Bikes - IMO - you don't want them to small, I'd much rather go to the longer tt and then change the stem if need be. For me, riding loaded, I like the balance a longer bike gives me. I hate feeling like I am perched over the bike, I like to be settled in the bike and become "one with the bike" I can ride a 52 or a 54 Surly LHT/DISC Trucker but like the 54 if I am using it loaded. When I was bike packing on the 54 I did put a shorter stem as I was a little to stretched out on the one that came with.
Salsa is a nice brand of aluminum - both Salsa and Surly are divisions of QBP. We don't have Salsa only because they wanted us to carry their entire line of bikes - yikes, We are touring specific so didn't work my business model. (sorry for the digress)
Lots of shops in Maryland, Looks like Joe's Bike shop carries both brands.
Sky King
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Gilles Berthoud "Bernard"
Surly ECR "Eazi"
Empowering the Bicycle Traveler
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