What device to use to chop/dice tomatoes?
Working as a cook myself... unless you really like chunky I would go with a blender. Issue with a blender about half the tomatoes will be a purree before you get rid of all the big chunks and if you start cutting up the tomatoes it wont take all that much longer just to dice em..

Blender quick but half will be a purree ?
Dicing  all of it will be nice even dice but takes longer.
Which is more important nice and chunky or speed?