Cons are more based on how the company is ran as a whole.
First, you get paid different rates depending on what you are doing. For example, drive time is minimum wage and office work is barely above minimum wage. At least the session are paid at a decent rate.
Next, at full time you are offered benefits, but the packages they offer are not the best.
Lastly, the criteria for full time is not consistent. You have to have 30+ hours for 4 weeks in a row, but you can loose full time status when you work less than 30 hours for 4 weeks within 6 months.