Another benefit of lots of subs is if your image train is undersampled -- such that you need to Drizzle. More subs = better drizzling performance (and a finer drizzle mist is possible, up to the point where you arrive at what you consider to the the optimal image scale). So there is a real balance to be struck. Because I NEED to drizzle my current setup, I tend to expose a sub for as long as is required, but no longer
