600W Solar - Getting 420W Max

I have 5 120W Solar panels flat mounted. I am in Mission TX at a FHU park for the winter. It is giving me a good place to test my system out. Back in the NE there are to many trees. I have seen a max of 420W and on the solar controller, with a high total of 197AH for the day. I see my gains on the solar seem to go with how low I draw the batteries down and how much I use during the day. I have not drawn the batteries below 12.4V by morning, so far. My average high solar amps is around 25 -30 amps. This seem good to me, or should I be seeing more with out tilting the panels? Thanks for any input I get.