I realize results are context-dependent, this is why everyone should make their own conclusions from their own analysis. You might have bigger bangs to make than shaving off some latency.
Did you test the other delays (100ms, 250ms, and 500ms) for long enough to get statistical significance in this context?
Yeah, people are used to slow web sites.
For example, if you are involved in a 3rd party bidding where you bid on some other network's impression, you'll have a deadline to respond with a bid. Let's say that deadline is 500ms (it's not). 100ms increase in median would lose _significant_ amount of impressions in that case.