I like to mix it up commuting, trying different gear and bikes. I've got 4 different bikes that I use for commuting, a touring bike, two sport tourers and a classic Italian racing bike. Today I rode my touring bike to work with panniers for the first time. I generally use a large seatbag (Carradice) or racktop bag for commuting, but needed more space for gear today. I bought a birthday present for my wife yesterday that was too bulky and heavy to carry in my usual bags, so I rode my Bob Jackson touring bike today with the Ortlieb front panniers mounted on the rear rack (full-sized panniers were larger than I needed).
The verdict? I must admit that the panniers worked much better than I anticipated. Of course, it was very easy to carry all of my gear and I threw in some extra clothes just to fill up the panniers. What surprised me was that the panniers didn't appear to slow me down, despite a steady crosswind most of the way and the usual hills on my route. Another nice surprise was how easy it was to unload. I couldn't lock my bike to the rack at work with the panniers installed, but the Ortliebs are so easy to mount and remove that all I had to do was simply lift up the bags and carry my gear inside. I definitely plan to use the panniers more over the winter because I often have to carry more clothing and gear when it gets colder.
I've attached a couple of photos with the Bob Jackson fully loaded with front and rear panniers, as well as lightly loaded with the racktop bag I generally use when commuting on that bike.