Amazon might be known for good support on the customer business, but I've not heard the same regarding AWS -- quite the opposite. If Google support were worse, it would have to just ignore you.
On the whole, I think the only thing they could improve would be to reduce the siloing between different offerings. When dealing with an issue that spans, say, EC2 and Route 53, I would expect their support to talk to each other and present a unified response to the customer rather than require us to deal with two separate support reps. But this type of siloing goes beyond support and applies equally to the AWS product.
Having said that, we pay for their 500$/mo support offering and the responses are pretty good. We're also split between AZ's etc as recommended.