I've been an amaysim customer for quite some time (phone data plans & broadband) and so far I'm very happy with the company. The provided value for money is very good compared to other, more expensive companies.
I have the broadband data only plan for my iPad, you can easily insert the SIM and be ready to go in a few minutes. The SIM can be bought at most supermarkets or sent to your home address for free.
It's not a look-in contract as you can cancel it monthly, which is a big plus for me. And at 15$ for 2 GB / 28 days, it fits even the smallest budget. There are deals available frequently, so look out for one of a those if you are a new customer. You have to be careful to not exceed your limit as additional data is quite expensive though. The Optus 4G plus reception works very well for me in central Adelaide, though I haven't put it to the test in more rural areas - it might have a few problems there. So far, I've always been able to stream series or movies on my iPad with no problems.
I've also had to contact customer service once about a small problem. As I'm not a big fan of hotlines, I chose to contact them by mail. I got an answer with the solution to my problem within 20 hours, which is still reasonable for me as it was on the weekend and it was not a very pressing issue. Faster customer service would be nice in the future.
To sum it up, I think that you get good value for very little money with amaysim. For those who want better reception in not so central areas or faster customer service, it might be worth looking at more expensive options.