Originally Posted by Nigeyy
Looking at the specs, it seems the Randonee is definitely a better bang for the buck with more appropriate touring gearing (especially if you are going up hills fully loaded). The only reasons I'd see to buy a 520 over a Randonee are:
1. you ride both, and the 520 is just better for you
2. if you prefer American frames as frame is made in the USA (or at least it was, last time I looked). This depends much on your personal opinion -where possible I always try to support US goods, but you also can't cut your nose off to spite your own face.
3. both bikes are equal in comfort for you, and you just prefer the colour scheme on the 520, and have the spare money!
Otherwise, I think you are looking at about $250 minimum difference in average price, and that could buy a lot of extra bike stuff. The only thing the 520 comes with that the Randonee doesn't is clipless pedals, and potentially the 520 might weigh a little less. From the specs, it looks like the Randonee comes with Tiagra STI versus barend shifters on the Trek, but that could certainly be evened out if you really wanted the barend shifters by ebaying the Tiagra STIs and you could definitely buy the barend shifters with the proceeds.
If I had the money, I'd buy the Trek, assuming the frame is US made. If I was short of money, I'd buy the Randonee. I'd like to see what a Trek rep would say.......?
The main reason to buy the Trek over the Randonee for touring is the geometry. The Trek has longer chainstays and a longer wheelbase both of which are longer by about an inch. This may not seem like much but it can make a difference in handling and bag carrying capability. Heel strikes on the panniers can become an issue with 17" stays where 17.75" stays give you a bit more room. Longer stays will also give a smoother ride.
I've toured on short chainstay bikes and they can have handling issues as well...they can get skittish.
As for the gearing, changing the inner chainring to a 26 tooth and the cassette to a 13-34 (things that can easily be done at the shop before taking delivery) would give you the same gearing as the Randonee. I've done many, many touring miles with just that combination...even here in Colorado
