It has taken all of our marketplace messages, from eBay to our website and combined them all into one easy to understand message inbox, it is ordered so your always replying to the most urgent messages first no matter which marketplace the message has come from, it also has a count down timer next to each message so you know how long each message has been waiting, particularly important when Amazon requires a reply in 24 hours.
One of the main advantages is that most if not all messages sent from a customer will import into one message thread, so if a customer is trying to play customer services off different representatives it is great for reading back through what has or hasn't been said, both by the customer and your own customer services. There are a number of other features such as auto reply's and folder sorting an flagging that we haven't used, but they seem like very useful features for some business.
One area that has helped greatly save time is the template feature that drags in customer information, allowing you to have a list of predetermined reply's but the emails are still personalised to the customer, with names, addresses, usernames etc all importable to a message.
Xsellco are always developing the platform and adding new features, live chat is something we plan to explore further in the future, all in all a great bit of software.
From a set up point of view, having to attach each market place individually for each country you sell in can be a long process, given the Amazon integration requires a little more work than the eBay sites also, that is more to do with Amazon and eBay, rather than Xsellco though.
Their is a lot too Xsellco also and option can be hidden in menus you'd not think to look in.
I think an ability to have a test environment within Xsellco would be beneficial for automated reply testing and generally helping you test templates etc.
The live chat does need fleshing out a bit, but as previously stated, they are updating all the time.
Overall not many negatives.