Save your money on cheaper bags that claim to be water proof, they aren't, only Ortlieb will keep your stuff dry and preform like it says it will. Truly the gold standard. Amazing product!
This bag is very well made, materials are bombproof, and the use of Velcro (usually a deal breaker for me do to lifespan issues) is backed up by a simple hook and loop closure. The bag came with a webbing strap for the head tube that is difficult to thread through the buckle on the bag, but otherwise setting it up on the bike was easy. Nice size for a long day out on the bike with a cold start and an undecided route, or just anytime you dont want your jersey pockets bursting at the seams.
Dont expect to access this bag while riding- get the Mag Tank from Revelate for that.
The Apidura saddle pack is very well contructed with high quality materials, excellent fastening system and it looks good too. Easily carries several tops, shorts and essentials for a multi-day Inn to Inn trip. It even has room for a small narrow thermos! My pack is a size small. I like its versatility to roll down small
(though it looks a tad sloppy when folded small) it's surprising how volumous it is when expanded, plus the top bungies can hold down my pair of sandals or vest. When loaded, I notice the bike remains stable and not out of balance. The loaded bag moves minimally. I opted for the non waterproof version. If any contents need to be waterproof, simply wrap in a plastic bag. Apidura makes high quality gear that is practical.
A solidly constructed bike bag. There's plenty of room for everything you'd want to carry. When getting off your bike, remember that the pack is there. I almost tipped over when my leg clipped the pack because I forgot it was there.