Final harvest is in, and the final decision is as follows:
Pruning determinate plants is a waste of time. Flavor is no different if you prune those as opposed to leaving them unpruned save for dead/dying branches. Fruits are about the same size, so that's not even a good reason to prune a determinate tomato.
HOWEVER
Indeterminate varieties benefit hugely from pruning. The taste and size was best on my small pruned IR plant than on the unpruned one, though the unpruned one gave out far more fruit. It's best to prune suckers and some branches on an indeterminate tomato plant if you want good-quality and decent size fruits.
Thanks for joining me on this experiment. Next year I know what to do with my plants, and the experiment will be mostly with new tomato varieties! I have Tom Thumb, Russian Black Sea Man (again), Indigo Rose (again, rooted from cuttings from this year though), and a surprise mix I received as a free gift. Roma has been completely phased out of next year's plans.