Opinions Or Pointers W/ Sd780is

That camera is giving you a lot wider area of experimentation than I expected. I think it's oversharpening the images - it's visible at full size, but not at posting size - and I don't think that's going to be correctable. So, there may be a point where you draw the line at distance because the sharpening will be noticeable when the image is downsized to 800 pixels (and this camera is perfectly capable of providing grading-quality 800 pixel images).

I am truly impressed with the SD780IS.

You will find the Gimp's Sharpening algorithms to be superior to any others, at least in my opinion. Sharpen last, after any adjustments in Levels or Contrast, and before you downsize. Be viewing the coin full-size, even if you're only seeing part of the coin, and have letter details on the screen when you do it. That's where the Sharpen effects will show up the most. Then back out far enough to look at the whole coin at once, to see if you like the result.

You should be able to use as much as 40% Sharpen on the blurriest images; I use 20%-30% regularly even on nice shots. Just because I can.

Always use the largest-possible image size. The smaller sizes just use less of the sensor; it's not like they'll be any sharper. The bigger they are to begin with, the more room you'll have to play with camera distance and therefore easier lighting.