I bought Battlefield 2 and it's DLC and one of the earlier Dirt games on EA Origin and it was an absolute nightmare. My games and the DLC would constantly not be authed in my account and I still have like dozens of support threads in my old mailbox trying to get things working.

At the same time Steam had polished a lot of the rough edges like this for their catalog and other publishers so there's really no excuse. I've never had to open support tickets with any other storefront because the DLC map pack for a game would stop loading while the base game kept working.