magneto as the potential to be an excellent shopping cart. but their are some things that they need to fix:
First and most importantly is the initial page load. On average its about 250k and takes between 7-9 seconds on a broadband connection. (28 or so seconds for a 56k connection) The reason it takes so long is the javascript they use.
Second, Seo wise it is not the best. Decent, but it needs some work. Regarding Magento's SEO solution, they allowed multiple paths to the same page, which can result in duplicate content within your own website (not always penalized, but is something to avoid).
last, If you have a lot of products, magneto is not for yo. it will take you much longer to list a product than pretty much any other shopping cart.
In summary, Magento is not really free. Yes you can download and use it for free. However you can not use cheap hosting with it. The reason is the amount of load it puts on the server. If you try to use it for example, you site will take forever to load and your customer will NOT wait for it.
