Single vs Double Stack PST

My goal was to compare the scope operating in both modes.  Here's the DS image:

And here is the SS image:

I found DS harder to focus; I'm not sure if the image is actually better....

I suspect the problem is with tuning the SolarMax filter.  I tuned for this image via the imager itself and this might not be the optimal way to tune it.  I'll try again, this time with visual tuning.