You've only been waiting 7 years for an answer, but I use a pair or Lone Peak P-100's. On tour, I mount them on the front. When not touring I take the front rack off (Tubus Duo) and just slap them on the back when commuting or errand running. They're built well and mount very solid. They use a bungee and locking hooks. They're really easy to mount or dismount for quick, small grocery runs. They never flop around even on dirt, gravel or uneven surfaces. I bought them in the "steel" color, which is really just grey (some online photos of this color look as if it has a slight bluish hue, but it's just grey). I like the simple color. I can put the rain covers on when visibility is a concern, and they have a reflective strip, too. Smaller front pocket as well as a very small pocket in the big compartment for some organizing, but I also tour with a saddlebag and a small handlebar bag and just strap the sleeping bag and tent on top of the rear rack. Makes a nice, balanced load. I also like their simple, classic aesthetic.

If I were to go the 4 pannier route for a large expedition or something, I wouldn't hesitate to grab another pair of lone peaks for the rear if needed. I wouldn't want to ford a river with them. I don't know how they'd hold up in a monsoon even with the raincovers, but they seem fine for not-so-fairweather use.