For my workflow, I prefer Icon Slate.
However, Icon Slate does not create icons in the legacy bitmap icns formats (it32, etc) and I found that out the hard way once my icons were in the field.
I needed icons in the old format QUICK, and iConvert Icons looked like it might do the trick. I rolled the dice and won. It gets the job done quick, painless, and at a very reasonable price.
Again, I prefer Icon Slate's workflow, but iConvert Icons saved my rear end and is worth every penny for me.
And now for the rant:
To all who complain about $5 for this software: seriously?
If you don't need it, don't buy it. If a different "free" method suits your needs, have a blast. If you paid for the program, and it didn't do what you expected it to do (or worse yet, it didn't do what it was SUPPOSED to do) then a negative review is justified. I attempt to contact a developer when I have an issue, and ALWAYS before I'm inclined to post a negative review.
If you want good software written by an indie developer who makes a living from his or her craft, you're paying to support the product, the person, and often their family. Don't throw any software, even packages made by established "big" companies, under the bus without doing some due diligence.
Have some respect, people.