You might be interested in something like the information at Wikipedia:WikiProject Medicine/Stats/Top English medical editors 2014. It shows how many bytes (file size) different editors added and removed from WPMED-tagged articles. You wouldn't necessarily want to run it very often for people with large edit counts, and it treats undoing a page-blanking vandalism the same as creating content, but I assume that the script could be adapted to run for all of an editor's contributions. WhatamIdoing ( talk) 02:33, 13 August 2015 (UTC)
You might be interested in something like the information at Wikipedia:WikiProject Medicine/Stats/Top English medical editors 2014. It shows how many bytes (file size) different editors added and removed from WPMED-tagged articles. You wouldn't necessarily want to run it very often for people with large edit counts, and it treats undoing a page-blanking vandalism the same as creating content, but I assume that the script could be adapted to run for all of an editor's contributions. WhatamIdoing ( talk) 02:33, 13 August 2015 (UTC)