Quantums is very easy to learn and use as it's well designed and has all the functions you would expect, however there are many options for customization that can be done to suit your own business needs and requirements.
The software does not have an option to create custom fields or report types, this was something we needed from day 1 but never found. It took about 2 weeks for us to get up to speed with the product and find our way around. We started using the software mainly to track and monitor our inventory levels, it works perfectly and allows us to see live stock levels, and also keep track of invoices and payments.