With the highest support level you do receive TAMs and Solutions Architects within AWS. They can add feature requests and make sure that influence is added for you and follow up directly with Product Managers to explain why a feature is important.

But, sometimes a high amount of spend on a service isn't really much more than the average. For instance, if you spend 200k/mo on a niche service then you'll get a ton of say in how things move forward, but if you spend 200k/mo on EC2 you might not be able to strongarm anything.