In gerrit there is a helpful option to diff versions of patches against each other.
Selecting one version disables all radio buttons for version selection rendering this a lot less useful than it could be.
(use diff-all side by side, expand Patch History, select one revision, then no other selection is possible)
|Field||Original Value||New Value|
|Status||Reported [ 10011 ]||Open [ 1 ]|
|Affects Version/s||2012q1 [ 11886 ]|
|Affects Version/s||2011q3 [ 11786 ]|
|Priority||Not Evaluated [ 6 ]||P2: Important [ 3 ]|
|Priority||P2: Important [ 3 ]||P1: Critical [ 2 ]|
|Workflow||Qt Bug Tracking [ 283897 ]||Qt Bug Tracking v2.0 [ 335127 ]|
|Status||Open [ 1 ]||In Progress [ 3 ]|