telu Considering most people would be playing with 1 character only, it helps a bit with progression since you would be doing the instance 1/day max.
Doing once a day would be way worse if you add party play into consideration. A party of 4 would be about 4x slower to get gears of some instances. This would be mitigated by the multiple runs a day.
This problem wouldnt obviously exist if people could make multiple characters in the ironman account, but it goes against the spirit of the challenge.