Disclaimers: This is the first genealogy software I've used, so I can't do a lot of comparison to other programs. Also, I am not a very demanding user, with just a handful of ancestors added in so far.

That said, I looked at a half-dozen other programs before settling on iFamily. Several were really ugly, either obvious clunky ports or just plain poorly designed. Some (especially the open-source PHP-based ones) were hard to set up and buggy and unstable once I did get them going. There may have been a couple of others that seemed to be similar to iFamily in overall appearance and functionality, but iFamily was the cheapest that served my needs.

Entering individuals is quick and easy, and linking new family members is also very simple. It's also very straightforward to add supplementary information like pictures or notes. The software stays out of the way most of them time, but does flag errors (my grandmother claimed her brother died 6 months before he was born, and iFamily gave me a warning when I entered that but then allowed me to leave it that way). Output is reasonably attractive and can be customized to an extent.

The one thing I really dislike is that iFamily keeps its data in a top-level folder and there seems to be no way to change that. Users should be able to select where to store their data, and at the very least Documents, not / , should be the default.

I have no idea how suitable iFamily would be for a power genealogist with thousands of data points (it may be great, I just haven't any way of testing it), but I think it's an excellent choice for someone like me who just wants to save the information that's been passed down through the family.