Optus has gotten into a tizzy, because a journalist claimed that their network "sucks" in terms of speed and performance. Optus (and other mobile carriers) constantly make claims that mobile "broadband" is equivalent (or better!) than fixed-line broadband.
IDC [presumably commissioned by Optus] said that mobile broadband is now more affordable, offers larger download quotas and is faster than comparable entry-level ADSL plans.
IDC couldn't have got it more wrong. That reporter was well justified in bringing Optus up on appalling network performance. According to IDC claims they "found the average download speed to be 1,747Kbps", and "latency averaging 447ms".
Sure, 1.7Mbps is comparable to 1.5Mbps ADSL1 (but it's practically dialup speeds when compared to ADSL2+). The latency on the other hand is atrocious. 447ms latency (almost half a second) is too laggy to do much more than basic web browsing. Say "bye bye" to voice over IP, online gaming, and SSH. In case you're interested, latency on ADSL is around 30ms. Dialup generally has a latency of around 250ms. At 447ms round trip time, any AJAX application (Google Earth, etc) will be excruciating.
With performance like this, it's no wonder that journalists pull up carriers about over grandiose "mobile broadband" claims.
The sheer fact of the matter is that you can't argue with Physics. Wire-line communications will always outperform wireless communications.