Ultegra 6700 wheelset - suitable for touring?

Though, evidence for the prosecution: I'm 90kg or so and my RS50s started breaking spokes after only a few hundred miles.

Quote:

heavy=strong?

not always, but in this case i'd say yes.

having said that, I use similarly built wheels to you all the time (RS80s) and i'm nearly 100kg. So you carrying 20kg of luggage on your bike isn't all that different to me just riding around. And I haven't broken them, yet

Personally I'd never put any significant luggage on low-spoke-count wheels. Plus they're straight spokes, which are an absolute git to get hold of when you break them.

i am 12.5 stone, use these on a whippett spec cannondale and am a fairly hard rider, perfect for me but i wouldnt put excess weight on them, they do have cup and cone which is useful for spares but low spokes, reckon you would be worried by them in a sharp corner fully loaded, maybe rs30? deep rims more spokes and cheaper.

They're not what I call touring wheels, but then what do I know?

These are my thoughts:

These wheels are light, and don't have a particularly high spoke count, and considering that you're planning on carrying panniers, I'm guessing you're not planning on riding this at race pace. Since speed and weight are already going to be compromised, a heavier wheelset isn't going to make a lot of difference either (neither is a lighter one). Go for sronger wheels.