We sit on 100 (according to GPS, not speedo). Have found it more relaxing to get into the left lane rather than fight for positions on the right. I find 100 is not too slow in terms of traffic flow, and [SO FAR] other drivers dont seem to get frustrated, yet still stay. My theory is that at that speed they are less likely to speed up, overtake then slow down in front of you because you are sitting at a regular 100km.
Doesn't always work...