I am just about finished setting up X-Cart 5 and I this version is PCI/DSS compliant using our Authorize.Net account with the Accept.js module which I set up and works in testing. Our current Authorize.Net credit card processing using AIM in X-Cart 4 (4.3.1) apparently is non-complaint with Authorize.Net AIM.
I have used X-Cart 4 since 2003, probably one of the company's earliest customers!! It worked well for our small non-profit organization to sell memberships and some books and other items or convention meets.
The new version will save us money on credit card processing and is even more graphically pleasing, and can be modified easily with different look and feel.
I am still testing and updating the pages, but should make this new version live in one to two weeks, replacing our old X-Cart 4 Review collected by and hosted on G2.com.