Panniers are an essential investment for a cross country ride. I imagine you could get by without them if you pulled a trailer, but I think panniers are the best way to go. Panniers are, in some ways like, socks. Purchasing them isn't sexy, people don't drool over them, but if they don't do their job it can be catastrophic.

I purchased a set of rear panniers made by Pacific Outdoor Equipment. They cost me $164.00 from REI. Overall I was impressed with these panniers. There weren't cheap, but were significantly less than some other brands. I have a few minor complaints about these pannier, but I would recommend them for someone considering a cross country ride.

Durability

The bags themselves were extremely durable. The nylon coated fabric seems impervious to scratches and cuts. I still can't find any scratches on these bags. During the ride, I felt good knowing that if a pannier were to fall off my bike it wouldn't break open strewing my gear across the road. 

The clips that attach to the bike rack are also durable. I was sceptical when I first purchased the panniers, because the platic clips seemed small, but I'm happy to say they don't show any signed of strain or wear after the cross country ride. I still use these panniers to carry thick books to and from school and they continue work well.

The one complaint I have about these panniers is the durability of the clips used to secure the roll top. On both sets of panniers the clips have broken. One clip started to break on the trip, and both have completely broken in the past few months. While I was able to use some string to make a temporary fix, not having the ability to sinch down the roll-top lid could seriously affect the waterproofness of these panniers. These clips seem to be the achillies heel of the panniers. While everything else about them is incredibly resillient, if these clips break it can seriously affect the usefullness of the panniers. 

Never once did I worry about the waterproofness of these bags. During the first few days of our ride, we peddled through many heavy rainstorms. Not only was rain coming down, but the many semi-trucks that passed us on the road sprayed substantial amounts of water from the road onto us and our bikes. While I was completely drenched it was comforting to know that I could change into a dry set of clothes when we arrived in camp. I also found to two outside zip-pockets to be waterproof. 

Size

For our trip, the size of these panniers was perfect. The internal compression straps allowed me to tighten the load next to my bike, but when we needed to carry a few days of food they were to be able to expand to carry that extra loaf of bread. To get an idea of what I fit in them, check out my gear list.

Ease of Use

Compaired to the panniers that my partner used, I was able to attach, reattach the panniers with ease. Inside the panniers are two smaller compartments that sit closest to the bike wheel. I found these pockets were just the right size for me to put some of my heaver items (stove & fuel, maps, etc) in order to keep them close to the bike. The two compartments seemed like just the right level of organization without adding too much weight. 

Each pannier also has a side pocket that zips closed. This pocket was great for storing our current maps and a few snacks. 

My one complaint was that it was sometimes a pain to open and close the roll top closure on each pannier. Specifically, if I wanted to access something from the main compartment in the pannier I would have to dismount my bike, instead of standing over the bike and twisting around. (I could access the side zip-pockets this way though.) A flip top lid, like seen some other panniers is easier to open and close. This roll-top lid also requires the use of working clips to properly close it. Because two of these clips broke on my panniers this created problems for closing the panniers. I'm unsure if you would get the same level of waterproofness with the flip top, so this could be a trade off for ease of use. For me I would rather have waterproof panniers and take a few more moments to open and close them. 

Specs

I copied these from the product webpage.

Model: BRF101

Size (in):  17 x 12 x 7 in. 
                  43 x 30 x 18 cm. 

Weight (lb): 3.75

Volume: 1687 cubit in.
                44 liters

Conclusion

I was very pleased with these panniers. For the money they provide lasting value and use. In the most important qualities (durability and waterproofness) they excel. The one weekness is that the clips used to close the roll-top lid are poor quality, but with some string you can get the lid to stay closed. Despite this problem, I would still recommend these panniers for a long distance bicycle ride.