I've been using this software since they first launched, so it's very reliable - once you train yourself in how things work (and there are many tutorials out their) it runs like clockwork! The layout isn't always intuitive at times, but with some training any issues can be resolved quickly through FAQs/tutorial videos available from support staff as well as customer service reps when needed.
Some features may not make sense right away; i recommend taking advantage of free courses offered by them or asking questions directly about what functionality does / doesn’t yet exist within your account setup. They help us manage our stock levels across several different platforms including Shopify WooCommerce etc.; we no longer worry if something has sold before getting confirmation of receiving payment details after shipping items due to ease of use.