If you value plan 3 at R300 (includes line rental), it makes DLS1024 R399pm (on plan 5), and DSL384 R199pm.
If you are an iBurst G3 user, this gives you R400 to spend on bandwidth @384k (+-6Gb), or R200 to spend @ 4096k (+-3Gb).
So it really only makes sense if you utilize a Telkom Landline to the extent where the closer plan 3 is economical. You then have the choice of 4x the speed or 2x the bandwidth.
However, for those with greater bandwidth demands, ie on G6 or G9, the benefits of ADSL over iBurst become far more pronounced due to the much lower cost of additonal bandwidth. At a marginal rate of R50/Gb (WebAfrica) vs R139/Gb on Iburst, power use is only really affordable on ADSL.
IBurst does have the 64k throttle, but similar ADSL add-ons exist for small change. On the flip side you have a lot of interesting ISP choices on ADSL ie prepaid, cheap local, unshaped, and uncapped offerings.
iBurst is not just an ISP, but a platform. To compete, it really needs to offer greater flexibility and affordability in its packages. The "mobile" card just doesn't play very well when it was clearly iBurst's intention in the early days to compete head-on with ADSL. They cannot now give up the fight on the basis that it is mobile. Those customers who bought into iBurst as the ADSL-alternative are not going to be happy.
If I want mobile I'll use 3G on my cell, thanks.