In London alone, Akamai have near enough 200Gbps of peering interconnect capacity. Add private peering and large ISP mirrors onto that, and you'll see what I'm getting at. Similar figures in Amsterdam and Frankfurt. North America figures are probably at least double that. They are one of the best connected networks in the world.
Apple are an Akamai customer. Find a nice big patch to download from their site and see what you get. In all likelyhood, any contention or restrictions in download speed will be to do with your direct upstream or their transit connections rather than Akamai restricting you.
On a test server that's rate-limited to 100Mbps, I have no problem achieving 100Mb downloads from Akamai any time day or night.