I haven't used the big panniers nor toured with them, but I have been using the front rollers for 20 years, both in front and in back. Bought my first pair for my rain/winter/city fix gear for commuting. 10 years later I "retired" them, replaced the hardware, set them up as rear panniers and bought a new pair.

Issues I've had: The hardware doesn't last forever but any bike store (and probably us) can order new for ~$35. I use two different LowRider racks with different diameter tubing and get a loose fit with the smaller unless I change out the filler pieces which I won't bother with. I punctured one of the old panniers with a very sharp kitchen knife. Called a local rafting company and they walked me through a permanent repair. (If it were rafting season, I'd duct tape both sides of the rip and call them when the water is low. 3M waterproof duct tape would make a temporary repair that would get you through the next 5 years. Home Depot.)

I love that they last virtually forever, the company supports them, the fabric is completely repairable, they are completely waterproof (I could use my 20 year old ones to carry water across the Sahara with a better rack and hardware - they'd be very heavy!) and the access and seal system is so simple and reliable. Also that they go on and off so easily. I lift them off when I shop, dump them in the shopping cart and have the checker put my food back in the cart. I find a quiet space, load the bags and drop them back on the bike. Carry into the kitchen to load the shelves and fridge. (Paper bags and my car is not easier.)

Oh, a comment on Ortleib and customer service - granted 20+ years ago: I bought the Otleibs because they offered yellow at a time when every body was making panniers in black, blue or red. Bright just seemed like on of those little things that might just save my life once and I would never know, but still a good idea. So I asked about yellow panniers at a few bike shops. (I was new in town.) One, a coop, told me that a shop in the city north of here had asked Ortleib to do a run of their panniers using the yellow fabric they were using for their rafts. Ortleib did. I asked the coop to order me a pair. They did and more. Now everybody makes yellow panniers and I see them all over town. (I've been trying the same with SKS and their road width fenders but no luck so far.)

My next panniers will be Ortleib - except I don't expect to live that long. Maybe the big ones if I tour again, but just maybe. I really like the idea of keeping the back of the bike light, loading the fronts with all the heavy stuff. So those small old fronts may just stay on as rear panniers that don't attract weight. (Tent and bag on the rear rack.)

Edit: elcruxio said it! "Attaching is easy and secure, they keep the water in and they are really quite durable against abrasions etc." Yup, if you do choose to carry your water that way. Seriously - another plus - if you are carrying food (shopping) they clean up like a pot. That easy. Hang them upside down on a clothesline of hanger from the bottom hook to dry.

Ben