Series vs parallel--When modules are in series, you will see a higher voltage at the controller but the amperage of the lowest module. When connected in parallel you will see the average of the two voltages and the amperage is additive.
If you have adequate wiring to the controller, parallel configuration will probably harvest the most wattage. In some cases, with an MPPT controller, a series connection may harvest slightly more, depending on the efficiency of the controller at certain voltages. Most controllers have a maximum voltage input and cheaper ones will self-destruct at that maximum. Better MPPT controllers just choke back the voltage and deliver the maximum amperage they are rated.