Never, ever, use them. If you are doing business with a company that uses them, stop doing business with them too. The only way to stop such an example of a company being paid to never deliver anything is to choke off their revenue at every supply.
They will never come. You will wait days and end up standing in line at their depot. They will update their system with lies saying they showed, yet just 'forgot' to leave a slip. Just stop doing business with these people. Have some respect for your customers.