I would also be part of the group that has no confidence in iBurst. Have been in an area that has had "Fair" signal, but was kept hoping that one day things will become better, due to iBurst explaining that they are always putting up new towers for signal. So signal should get better over time. The connection (without any external hardware) was fine up until 2 to 3 years down the line, out of the blue it started degrading in signal quality. I had to add a panel outside, which improved things for a few months, but then things went back to "worse". I then went and sourced an omni antennae, which improved performance slightly, but not that much.
Ended up deciding to stop with the irate phone calls to people at technical support, and just quit the service. Have been on ADSL for over a year now, and have not regretted a single day with fixed line.
iBurst have great data pricing, but their wireless service in some areas, is not worth the effort it would take to get any assistance.
I say leave them. Your money is better off elsewhere.