The way QGIS draws the canvas when panning is quite annoying. If I pan the map even a little bit everything goes blank for a second or two before the layers are drawn. It looks like this happens only when the layer content is supposed to be downloaded (my PostGIS layers are drawn without hurting my eyes), so this might be just a problem with the configuration rather than the code. Does anyone have a solution?
Oh, and the question should be "how can I make QGIS suitable for epileptics?". It's that annoying.
EDIT to pose question for QGIS 2.4 onwards:
This still appears to be an issue in 2.4. There seem to be some helpful setting under Settings > Rendering but these don't help the issue. QGIS just lacks the nice, slippy, smooth feel of other map viewers. Is caching still on the cards?