The best thing about this software is it's ease in use, I can easily add my clients or customers into the system which makes scheduling much easier! It also has great reporting features, allowing me to keep track of all invoices/payments made by each client.
There are some things i dislike as well; there could be more options when making payments (i would like an option other than "Payment Approved" & "Approve Payment"). Also sometimes the interface isn't very clear so having someone else look over your invoice will make sure everything looks correct before payment approval. Great program overall, but if price was lower then maybe they wouldn't have had problems filling their customer database? We've been able to solve our billing issues using hiRez flex for agencies.