As a developer there is not a better CDN in the world than akamai.
And as an end-user I'm telling you that this is simply not true (at least for the service level CBSi are at, there probably are different price tiers?): Just because you now are able to download swiftly doesn't make the same true for everyone.
Downloads speeds from GiantBomb and GameSpot have consistently been extremely bad for me, I used to get fantastic download rates before GiantBomb switched their CDN. Plenty of other people have also complained the last few months, I can't be the only one.