Thanks for linking to my blog, Troy, I really should do a follow up to that post. While I did try to make use of other terrain editors, I found that I ultimately had to do a lot of work to finesse their output to work in
SL. I pretty much use Photoshop all the time now for terraforming. One technique that yielded really nice results was to draw a terrain like a topographic map in Illustrator, fill in each height level, and then take it into Photoshop and use Gausian blur to smooth it all out. Ultimately, you're going to do a lot of smoothing in-world to get it to look right, no matter what you use. Also, these days, if you're technically inclined, you can run opensim on your computer and use it to quickly preview your work rather than having to do the uploads and downloads of the RAW file to
SL, which takes a long time and is a hassle if you're not the Estate Owner.