I did the Pragelpass yesterday, in the reverse direction as reported above by dakman. Its a neat 60km from Brunnen to Ziegelbrücke, and took me just under 3 hours.

The climb is certainly one of the steepest I've attempted recently, and the first couple of kilometres are mentally and physically challenging...but it is a pass that seems to get easier as you get closer to the top. And the decent is enjoyable with few suprises, and a glorious view over the lake as you race towards Glarus.

A few points:

• If you follow the Veloroute 83 signs out of Brunnen, you encounter a 1.5km section of gravel after 5km...its quite smooth and no danger to a roadie if you take care. This seems to be a reasonable trade-off for the short cut that it makes.
• Make use of the 15km to Muotathal as a relaxing warm up...conserve energy for the climb.
• Be careful attempting it on very warm and sunny days. You're average speed might still make it difficult to cool down, regardless of how much water you drink.
• As with most passes, take a jacket with you. I sweated my way up from the 23 degrees at the valley floor, only to encounter fog and 13 degrees when I got to the top.
• The road surface is okay, but poor in comparison to wider passes, with plenty of cattle grids. Watch out for post buses on the way down to Glarus, they like to take the whole road especially at corners).