I really wanted the Vaude's, but was unable to find them in the shops I visited to be able to have a look first so I ended up purchasing the Ortliebs and they are really nice so I'm happy.
As far as durability and waterproofness... both appear to be equal so you end up selecting based on capacity, looks and other functions (ease of mounting, ease of access, etc). You're selecting very like-for-like products though, so I'm sure you're going to be good no matter which one you buy.
I really wanted the Vaude's, but was unable to find them in the shops I visited to be able to have a look first so I ended up purchasing the Ortliebs and they are really nice so I'm happy.
As far as durability and waterproofness... both appear to be equal so you end up selecting based on capacity, looks and other functions (ease of mounting, ease of access, etc). You're selecting very like-for-like products though, so I'm sure you're going to be good no matter which one you buy.