I have to agree with RD that those FT3 craters are pretty, um... inadequate?
If you are willing to shell out some money, the Flaming Pear LunarCell filter for Photoshop does a pretty good job making craters. Large numbers of large craters with very little other texturing gives a very nice Ganymede-like effect. If I didn't already have PS and the Space collection of filters from Flaming Pear, though, I doubt if I'd get them just for that purpose.

There aren't a lot of good crater generators out there unfortunately. Sadly, even PlanetGenesis can do better than the example above. Wow.

I'm pretty sure there's a way to make somewhat serviceable craters in Wilbur, but you have to plant them individually.
I think maybe I could reproduce the coronae from LunarCell and maybe the rays, but the cracks would be complicated.

Time to write another blog post, so maybe I'll research to see what I can do for this.