TL;DW:

Old client isn't a strict advantage because:

You cannot use decimal maps Increased storyboard lag Less Song Lead-in is a problem because sliders can instantly pop and cause you to miss a sliderhead, and force a retry

Old client is as much a strict advantage as multimode/ctb only?

Invalidating tens of runs without a discussion was silly and needs to be re-thought out.

on my current 100fc submitted run i fc'd 50 beatmaps in 19:25(.500) I've counted the maps myself to make sure i haven't missed anything, was just wondering if it's worth submitting for verification as it'd be the world record by a large margin.