The best part about working with flexplm has been their customer support team! They are always willing to help you out no matter how small or big your issue may be.
I can't think of anything that we dislike at this time but if there was one thing it would have to be they need more customization options in some areas. For example, our shipping department uses them heavily so having different labels created especially when sending items across states could really benefit us all by reducing mistakes made during shipments. We use flexplm mainly because its easy to navigate through as well as customize what information gets sent to customers who purchase from us online via ebay/amazon etc.