Slic3r vs Cura

I can't decide which is a better choice for slicer. Both have their advantages. I printed the same STL today with almost identical settings. I think Slic3r did a better job but the top and bottom layers are ugly. Take a look and let me know what setting I need to change.

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Slicer on the left, Cura on the right. There are some weird ripples in the cura print. What are those?

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Slicer on the Left, Cura on the right. Bottom layer on the Slicer is terrible, not filled in at all. What settings can I change to get the bottom layer to print more solid?

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Slic3r top layer


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Cura Top Layer


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Here is another print, this one with the most recent experimental version of Slic3r. I occasionally will get thick lines in the print like the one I tried to picture here. It looks like one line of extrusion is thicker than the others. What could cause this? Bad filament? Pressure on the spool? Temp fluctuations?

I have often wondered if the 30amp power supply is up to the task of heating the 12" bed and running the nozzle. Often the LED lights I have hooked up directly to the power supply will flicker. That can't be a good indication of a stable power supply. They only seem to flicker when I hear the heat bed relay click open.