Number of rounds and battlefield size
A point of the neoroborumble was to make it a new rumble. Not just the roborumble but shorter.
I wanted to prevent wholesale moving of robots from the roborumble to the neoroborumble. Changing the size means people at least had to go in and adjust bots in which the field size is hard coded.
I really jsut like 3 battles more. 1 battle doesn't really tell you enough about its early behavior, except if it got unlucky position or not.
I like 3 much more myself, but it is opinion based.
But mostly because 1 seemed to hit the server hard and fast and constantly which is not so good for the poor server. 3 seemed more acceptable in the time it took before uploading again.
Telling me that 'you don't care' doesn't make me want to change my mind so much.