Having my system be portable has given me a chance to see what it can do for us flat/tilted/tracking compared to our needs and general weather patterns before I mounted it. Now I KNOW 230w mounted flat will cover our needs most days and a decent bank will cover a few cloudy ones.
I also know that the expense of mounting two matching panels and a bigger MPPT controller isn't going to benefit us that much. They wont cover us in heavy cloud cover where I can get only get 4a even tracking and will be total over kill the rest of the time.