I/O performance is still abysmal even on their largest instance type when striping over 20 EBS volumes (I benchmarked that a while back). And we still noticed a high variance in I/O performance during peak hours despite the striping.

Any recent dedicated server with 16 spindles will completely annihilate EBS in terms of IOPS. And that's with plain old spinning rust - add some SSDs and EBS ain't even in the same ballpark anymore.