My current store is running on oscommerce and it is extrememly modified. It is the old version 2004 and would like to upgrade to something more up to date. I was looking at upgrading it to the latest cre loaded version but the seo contribution I have installed is different from the one that cre loaded uses and therefore I would lose all my seo effort. Since I will be losing all the seo anyways I started looking at other carts such as magento, cubecart, cs-cart and so on. I'm stuck on deciding which way to go. I could alternatly also upgrade to version 6.2 of cre and install the old oscommerce contribution and I wouldn't lose my links but that in the future if I ever want to upgrade again I will be faced with the same issues.
Magento I've found is good but a steep learning curve, and last time I tried it, it seemed a bit "unpolished" if you get me, the odd bug etc still and needed a few more months to mature I've recently just tried Interspire Shopping Cart, although this is a paid solution it's a VERY good piece of kit, very easy to use, plenty of SEO features (SEO URLS, Meta Tags etc) and it comes with an excellent range of pre built templates