It really was great for a time. It felt so good to get my stuff off of my back and be able to move freely. My only issue was the limited space and lack of true water resistance. I was commuting more and more and even into the cooler winter months. And there was no way that I was going to fit shoes, jeans, shirt and jacket into that little thing.
I tried to add a set of really cheap panniers to the equation, but it was still a pain getting everything in. It made me dislike the process of getting ready for my ride. I had to play Tetris to squeeze everything in, and when that takes a half hour, you find yourself not wanting to ride (which is ridiculous to dislike the ride because you dislike the prep).
Eventually, I found myself at my bike shop's annual "sell-everything-for-incredibly-low-prices" sale. These Ortiebs were on sale for 75% off. I nearly wept in the store... Okay, not really. But they were EXACTLY what I needed. They are actually for touring. So there's an obscene amount of space in these things. I can fit three days worth of work clothes (well, work clothes for me are jeans and a t-shirt) on one side, throw a laptop and books in the other and I'm good to go.
Getting ready is easy. I toss whatever I need in there without wrestling or folding tightly.
They've seen torrential downpours of rain, feet of snow (pictured here) and been beaten around without any issue. I highly recommend them to anyone.
So, if you're riding with a backpack, I'd say anything is better than that. But if you've got the money to spend, jump into a nicer pannier like these.
Get out there.