Recently we did a magento commerce website and saw its raw potential in ecommerce.

Magento has surpassed all other platforms we used earlier in its features like CRE Loaded, OsCommerce, Ubercart or Wp-Ecommerce.

Magento has not only got umpteen shipping calculators but also great apis to be integrated like USPS, Fedex and blogs, cms and also bank gateway modules.

I reckon using Magento for all the other websites.

The websites we were talking about are: one.goprolocal.com/magento
http://treasurehouseaccessories.com/magento/

Regards,
ShriKrishnaTech