If MTN can do this here, why don't we see this more often elsewhere?

I do speed tests on my connections all the time. I don’t get out much and this, along with website terms and conditions, is a bit of an obsession for me. I see speeds like this in areas around Johannesburg on some days and really lousy speeds in most other areas and I wonder why we don’t see more consistently fast transfer rates on MTN’s network? Is it a topography thing? Equipment?

By the way, I did these tests using my new iPad. My iPhone 4s was getting just under half these transfer rates on MTN earlier.