Panniers - Racks - Bags - Bike Luggage

The sqr slim looks nicer and is easier to use as it has a drawstring to close the inner and a single clip to close the flap. The side pockets are not great on it and it is difficult to get them secure if they are not full, ie if the pocket is only half full the flap over the pocket leaves room for potential loss of items as they rattle around. Generally this closure parts work best when it is more full. The inner pocket has a Velcro closer which is not all the way across.
The carradry has the zip side pockets so no chance of losing stuff and the main section is has variable capacity if you’ve more kit to carry. Worth the two fasteners on the main compartment flap it would be possible to stuff wet kit behind it so as to keep the main compartment dry. This would be much more difficult on the slim with its single fastener. There are two internal compartments for documents or small valuables. Both are zipper closed and one is removable by popper fasteners.
I use the slim for commuting. It takes my laptop and clothes bag (no shoes, trousers or towel) easily.
I tend to leave them on the bike when in use as have my clothes in a separate bag which I carry in and out of the house/office.
Hope this helps.