I have just migrated my website from WordPress to Drupal, so if you run across any bugs I apologize while I get the kinks figured out. I discovered the hard way Disqus comments do not migrate well, even if its just across platforms and no URL changes.
Drupal Commerce is an amazing open source ecommerce solution; with its foundation in Drupal it can easily contend with the big cookie-cutter ecommerce solution companies. Except for one area - reporting. Drupal Commerce and reporting seem to have missed each other while its growth skyrocketed. I mean, there are ways to build reports and show your store's revenue...just nothing "perfect," in my mind.
Free shipping offers are a huge request in Drupal Commerce. Here is how you can use one shipping calculation rule to provide free shipping without making new shipping services or modifying existing ones. Typically tutorials have you create a new "Free shipping" flat rate service that checks if the order is greater than XX and have your other services check if the order is less than XX. That's neat, but sucks if you or your client is just trying to offer a sweet deal for a month.