Deep cycle or starter battery charging issues

I just installed a similar sized solar system and am upgrading with another bank of 2-6V GC2's. I chose the Sunsaver MPPT-15 controller for a few reasons. First, Rogue is not selling their new controller yet and I'm unable to wait. Second, Morningstar's reliability as expressed by users. Third, the capability of programming and data logging with a serial interface to a computer. The serial interface and software does all of what the Trimetric does but is not as handy as looking at a monitor. I've installed a couple of analog gauges so that I can see what's happening at a glance. Fourth, price, I bought the small MPPT controller for $200, a lot less than it's bigger brothers.
Thanks to all the members that have helped with my solar installation and advised me on the pertinent details.