This version brings some significant under-the-hood changes that will (hopefully!) not be visible to your customers, but are still significant. There are also some updates for digital products to make renewals easier.
Most importantly, the "Product filters" now use XenForo's "Custom fields" feature. This means that rather than needing to define product filters in every single category, you create them all once and tick the available ones in the category, and then choose them in the product as normal. This has the additional benefit of being able to translate these product filters into multiple languages, if that's something your storefront could make use of.
The second important change is that sales now use a "type handler" system internally similar to product types, which opens up the possibility of creating different types of sales in the future.
As for user-facing changes; if your storefront sells digital licenses, your customers will now see a list of their existing licenses and a button to quickly renew said license, in the sidebar when browsing a product. You can see this in action @ my website, and you should totally click the "Renew" button as well
If your storefront doesn't sell digital downloads or physical products, the post-purchase redirect flow now makes a bit more sense.
There's a few other features, changes and fixes added to this release, please see the full changelog for more information.