I don't know if this is more of an aesthetic question or electrical. I am adding 2 recessed lights to a small bathroom (5'x7') and would like to know if there is any particular size to use. I was going to go with the 4" but saw 3" models and started to question my decision. Is there a big difference between the two lighting wise? They do use the same watt bulb but is the smaller size just a more concentrated cast. Any thoughts?