[iharris]

Yeah, for me, 1d experiences the lowest load of all zones. According to the pricing history for spot instances, 1d experiences the fewest price spikes compared to 1a and 1b. I'd be interested to see if other users have noticed the same thing for their zones.

[biot]

I find that random(5) is the best performing. For okay but consistent performance, random(5) is decent, but you should definitely avoid random(5) due to high load.