You also forgot the rather excessive CPU and network usage that Skype has.
Yes, that too, thank you. :P
Skype doesn't take long to send an receive messages...
MSN/WLM ones it does, yes. I've done several tests by having WLM 2012, Skype 6 For Windows Desktop, Skype 6 For Windows 8 (the app version), and the Windows 8 Messaging app all open and running at once, as well as other combinations of them open and closed, and every time WLM 2012 beats them all,
easily. There are even times where messages will come in up to 20 minutes after WLM 2012 has already received them.
Simply put, Skype was never built to handle true instant messaging...especially that of MSN/WLM's networks. It's not a fault of Skype so much it is a massive failure on Microsoft's part, but it's still a gigantic turn-off for me in the merge because it makes it entirely pointless if the messages are not received instantly in the instant messenger. Until Microsoft fixes this and the other issues I have previously mentioned, I will continue using my workaround methods to run both Skype and MSN/WLM together. I'm especially not losing my ability to communicate with Yahoo! IM users just because Microsoft is too lazy to patch Skype to enable it again, when their networks have already long since been supporting it for MSN/WLM for years.