The customer service is excellent, they are always willing to help with any questions or concerns we may have along our journey of using their product! They also provide great support for new releases as well - so that's awesome!! I wish there was more flexibility in how my books were displayed but this isn't something which has been brought up by me nor do i expect it anytime soon.
It would be nice if some customizations could take place within your account page itself (as opposed to having to contact them) rather than via an email asking specific details about what changes can/cannot be made etc. We use lemonink because it allows us to easily upload all our existing titles to one platform, plus gives us access to additional features such as being able to sell multiple versions at once without needing separate accounts.