Solar panels can either be polycrystalline or monocrystalline. The differences between these describe the purity and structure of the silicon used. Practically speaking monocrystalline solar panels tend to be slightly more expensive and slightly smaller due to the increased efficiency (increased purity) of the structure of the panel. The factor of comparison however, is the rated output.
A 250w panel will generate the same amount of power if is mono or poly.
Often we find customers are very interested to talk about the specifics of the technology, but the reality is the Australian environment can be one of the harshest in the world. This has a much bigger factor in choice for our customers. The most important thing to pay attention to is the person installing it and the quality of the product. Unless you have roof space issues or other complications, you could probably use a variety of technologies to achieve electrical independence.
Another common misconception with respect to quality is the country the panels were produced. There are some fantastic Chinese manufacturers and some terrible European ones, just like cars. More so, because the price to the consumer has fallen quite significantly (along with power prices skyrocketing) the market in Australia has become a lot larger, thus we see more entrants into the market.
In order to make the best decision around choosing solar panels, chat with your solar consultant. There will always be a tradeoff between quality and price, but thankfully Australian consumer protection laws and warranties keep most of the nasty brands away.