Performance aside, here is what I hate about Skype compared to MSN / WLM: privacy. (1) Skype logs you in to your last known status / on MSN you could choose before login (for example, "appear offline"/"invisible"). If I just want to check if a contact is online without my aunt start chatting, I can't. (2) There is no easy way to block whole contact groups temporarily. When I'm at work, I don't want my friends to see me online; when I'm at home, I don't want to be contacted by co-workers. (3) Say I'm chatting with Bob, and he goes offline just before I send him a last IM. This IM will be delivered the next time that we are both online. Even if one of us is "appearing offline"/"invisible". So we have a way of knowing when someone is hiding: just send someone a message when they are offline. Bah. (4) Not related, but the delivery of old messages is awful across platforms. What annoys me the most about these bugs (1-3) is that they seem so easy to fix, and yet nothing is done. Meh. Do you have similar frustrations?