The add-on itself is the same for both tiers, so no, Premium does not come with more features than standard.
Its mainly benefits (like Premium can access all releases, where as Standard can only access Stable/Supported releases).
Looking at each of the add-ons in the Products Section, teh do list most of the benefit differences if you compare AMS Standard to AMS Premium.
Example...
AMS Standard license.
AMS Premium license.
It's the same addon, just that Premium license come with more benefits (some of which are not listed).
Premium license also include access to my Private Support site, which is where advanced support is handled (other than Tickets).
Premium license holders also get a discount for Custom Development (a significant discount I might add).
Premium license holders also qualify for After Hours, Weekend and Holiday support (paid of course).
Premium license holders also qualify to purchase Private Addons and New Addons being developed (like EMS aka Event Management System).
Premium is by far the most popular choice (about 65-75% Premium license holders).
Hope that makes sense and is helpful
