I could use a pannier but in general

1. They cannot be carried over the shoulder when off the bike
2. They do not stand upright when you are loading or unloading them
3. They are tall and narrow making them awkward to load and unload
4. They do not have a large enough base to carry things flat
5. Their reflective sections are not ideal for a cross bike mounting position
6. They may carry less than the crossrack bag
7. Good ones cost more than the Crossrack bag ($30 when bought with Crossrack)

The Crossrack bag may be better in some or all of thees respects but I find it difficult to tell from the website.

I currently use the small orange version of this http://www.cascadedesigns.com/sealli...n-tote/product and find it great. Its tough, completely waterproof and very light but I'm not sure how easily and effectively it would fasten to the Crossrack.

Another possibility is this http://www.mec.ca/Products/product_d...34374302693353. My wife loves hers but they are not waterproof and if mounted across the bike there may be too much lateral load movement.