It also depends on the exact variety. I grow Sakura which is a cherry. I pinch out the side shoots for the bottom foot or so then I let it do its thing. I never pinch out the top unless it gets too far above the crop bars so that I can't crop it. Every plant is laden with fruit, loads of trusses and the plants are 8' tall, cropping well into November, sometimes December - and this is in southern Scotland at 1000' above sea level (in a polytunnel). For typical large-fruited tomato plants you would pinch out the top in late August after 4 or 5 trusses were set to give it time to ripen the large fruit.