I compared PWM with MPPT in the past, and found they come out fairly close because with MPPT you have the buck converter in it, which uses the input POWER which is reduced by the panel heating up in the sun which reduces the voltage component in the power.
The PWM controller just passes through the AMPs which are not reduced by panel heating (they go up a little in fact)
You can still get a little more from the MPPT at times, but it is trivial for RV camping.
This summer I had a different solar set-up and got to play with three 100w panels and an MPPT controller. I tried series vs parallel with them and got the same amps either way when there was no shade on any panel. I was not able to run a comparison of series vs parallel in low light. In low light there are hardly any amps anyway, so there is not much to be gained with a small array from that I figure, even if it is better in series then.
BTW, I got this 20a controller when it looked like I would have two 100w panels, but then I got a third so I should have bought the 30a version for an extra 20 bucks. Mistake!!! :(
The 20a version is not limited to 20a as such but has a 260w input limit, which has the same effect. So my 300w array was acting as a 260w array. But now I got to play the "over-panelling" card when the array woukld only be collecting under 260w anyway, and that was when the third panel got to do some good. I should still have chosen the 30a version though.
http://www.wegosolar.com/products.php?product=EPS%252dMPPT%252d20-EPSolar-20-Amp-12%7B47%7D24V-MPPT-Solar-Charge-Controller
