I think to speak about Prestashop first because when compared to its counterpart, Prestashop comes with easy to installation facility. This platform has user-friendly interface and Faster search options.
You can find module and theme in the add-on.
E.g: https://www.youtube.com/watch?v=_mU38sk4nvU
https://addons.prestashop.com/en/visual-products/28536-lookbook-product-collection-showcase.html

I'm a web developer and I choose Prestashop because It 's such easy to install and modify a module or theme. I can integrate my website with a special blog, Instagram feed ... by modules.
E.g : https://addons.prestashop.com/en/sliders-galleries/26058-feed-pro-social-network-image-gallery.html
https://addons.prestashop.com/en/blog-forum-new/25908-blog.html

It's the pairing I would most like to see

Integr8soft have just finished a module for Prestashop 1.4 to integrate with Xero. You can see it working at http://www.youtube.com/watch?v=1nqfrGprzGk&autoplay=1&rel=0

The main service is offering 3 month's free for early adopters of the service at http://www.integr8soft.com

I am a prestashop developer for many sme's in Australia, and can positively say that a fair majority of them would use xero (some are already considering it anyway) if there was a simple prestashop integration...

This would be a great feature. We currently use prestashop and to stop the double entry would be very useful.

We also have a number of client using prestashop who would shift to Xero if the process was straightforward

We currently use Prestashop for our business using it's invoicing and delivery slips. Would be great to have xero integration so as to do away with double entry of info.

PrestaShop is a must for eCommerce integration. Please, please, please! We use this for numerous online retailers and would be able to shift the lot onto Xero if we had this!