Right, like the fact that an instance can have only one ip address. Virtual hosting for multiple websites with SSL goes right out the window. There are a couple solutions to this problem, but they're either impractical or just plain unacceptable for production boxes. All platform choices have these kinds of gotchas and/or extra costs for things that are just free if you own the server. I use AWS every chance I get, but sometimes a project requirement forces you to go dedicated.