Glad you've been getting some great quality prints using Creator and welcome to the boards! While the software comes with some very intelligent presets, it can also be very easy to make a few minor changes that significantly impact print quality. You probably have a much better chance at getting spot-on advice if you post the .fff file you have been using to print your calibration pyramids. I can tell you from experience, that things start to become very tricky at extremely small layers heights, so you might want to try printing one of the pyramids at a 0.15mm layers to see if it helps isolate what factors might be effecting your results.
In fact, we print calibration pyramids on our test machines all the time, and we usually get great results using the default settings. The screenshot below is using a stock printer, stock filament, and default settings included with Creator. Literally no tweaks at all, straight out of the box
In reality, we can get much better results if we actually tailor the settings for this specific part, but I just wanted to illustrate what the default settings should be capable of doing.
Now about your question on extruder coasting, this is similar to the old dwindle features used in skeinforge. When you are printing you can build up significant pressure inside the extruder trying to push the melted plastic out the tiny hole in the nozzle. The coasting feature allows you to turn off the extruder a few millimeters before the end of the tool path to allow this pressure to equalize without leaving blobs on your part. When combined with well tuned retraction settings, it can be a very powerful combo. Few other slicers actually support this so it can make a big difference in your print quality!
Hope that helps and let me know if you have any other questions!