Amber,
Hello! I used the free version for a few weeks and liked that it can be made "public" by providing a link in your signature file... can't do that in the PC version since all the data is stored on your PC not a public server...
But what I did not like about the free version was that entering foods made from a recipe is a real pain in the tuckus! You have to figure out manually what percentage of each ingredient you just ate and enter them separately as "whole foods" (like flour, sugar, tomatoes, etc.)
The PC version lets you create a recipe, how many servings are in it, and then you just tell it how many servings you ate... poof, all done!
You can also create custom foods in the PC version, which I don't think you can in the free version. Like say, MF Dutch Chocolate 55 Shakes!
I think the PC version is totally worth the small cost. Plus it has all kinds of neat tracking tools, like measurements, weight, and lets you create graphs based on them. And you can see how much of X you ate over X days or weeks, from carbs to Vitamin A to Copper... you can get really OCD over what you ate and drank hehehe!
There is a little "tour" you can take online of all the features in the PC version. Also, I had to ask their customer service a question and they got back to me almost within minutes and were very thorough with answering the question... I was impressed. I had asked them why the software rounded up or down fractions in data entry when entering label info, and they told me it only does that on the surface for uniformity, but really, it does tracks fractions and uses them to calculate any multiples... in case you're a data nut like me!
Summary: great piece of software!