Here is a speedtest I done with my two simcards in my HSDPA E220 modem connected with 3g only option. MTN connection would not even allow a full test through internetfrog.com test, so I stuck with numion.com.
It is important to note that MTN test only succeeded when there was a BURST of data that could go through. For some reason MTN connection has long dead times (30 seconds plus) followed by a quick burst of data transfer. So pathetic.
26 March 2007, numion.com speedtest
Vodacom @ 9:56pm
Download speed: 354.01 kbit/sec
upload speed: 56.73 kbit/sec
Latency: 1276ms
MTN @ 10:02pm
Download speed: 68.58 kbit/sec
Upload speed: 31.71 kbit/sec
Latency: 1220 milliseconds
BTW, this test was done using "internet" APN in both cases.