I use the one with the deployable panniers. It's a solid bag, and I love that I can take it off and put it back on so easily. I also like that I have the pannier space if needed. When I use this bag, I have the Cygolite Hotshot that I clip to the back of the bag, and the two seem to work well together.
That being said:
1- it's not waterproof, only water resistant. If you plan on riding in the rain, you'll need a cover or put your things inside plastic bags.
2- the side pockets are nearly entirely consumed by the panniers, but there is a little extra space in there. Unfortunately, it's all in the same compartment, so say you put your phone and keys in there because the top is full and you wanted quick access. Later in the day you take your jacket off, but you need to deploy a pannier to hold it. First, after unzipping the pocket, you must remove your phone and keys, deploy your pannier, and then stow your phone, keys, and jacket. I wished there was a separate, thin zippered pocket between the pannier and the main compartment for small items to remain in the side pocket even when the pannier is deployed.
3- after riding in the rain, the rail can get grit in it, so it'll need to be washed out occasionally.
4- make sure the bag is in the rail. It's easy to slide the bag on top of the rail and not get a secure connection.