I had a few problems transferring the site from my local MAMP set-up to live server. I found after transfer from my MAMP set-up to a Linux server that it had functionality problems. The Mijo support team simply reinstalled the component for me on the server which fixed it all.
The support via the Mijo ticket support system were very responsive and they typically replied within the hour. Brilliant.
Uploading 11k products into the MySQL server went without any serious hitches and Mijoshop picked it all up nicely.
I'm starting a new project and this will also feature a Mijoshop store. I have been pleasantly surprised to find template widgets (YooTheme) work easily in the products and with the categories so you can make it look quite integrated. Plus there's a host of (and some free) opencart vqmod files that are easy to install to adjust functionality.
Other than that, I have no reservations. Recommended.