I started out trying the no pruning at all this year, but it turned out that the overlapping branches eventually shaded the interior to the point that interior foliage started to die-off. The outer matted vines also made it very difficult to harvest fruits hanging inside.
So I HAD to start thinning the branches to open things up.
Next year, I'm going to try something different. I'm going to try "espalier" training tomato vines on evenly spaced wires, kind of like grapes, but maybe 4 or 5 wires 12" apart (still noodling the idea at this point
). These are going in my Front Yard Fence Row. They should look interesting....