I agree that better visualization tools should be made available. Most just use the same tired pie charts and bar charts.
I see you posted an example of adding color to show an extra dimension of http status code. That makes 4 dimensions. An interesting 5th dimension would be to have multiple graphics similar to what you havex, but break them up by response time. This would be a 'small visualization'.
For example repeat your graphics for pages that take from 0 to 1 seconds, 2 to 3 seconds, 3 t0 4 seconds, 4 to 5 seconds, 5 to 10 seconds, > 10 seconds (or something similar). Patterns may emerge along this dimension too like 404 errors during long page executions. Or slowness based on time of day.