You're right. We use Skype.
Skype has always had the reputation of being a rather pathetic IM service, and this doesn't seem to really be changing. I actually use it quite a bit (for calling at a certain area I frequent that doesn't get reception, but has WiFi available), not sure how much use it gets from people here. It's bad, and even the Stock Google Talk app in Android runs circles around it.
Voice Call Quality is decent, but it uses almost twice as much data as Google Talk Voice Chat (which translate to significantly higher battery usage). Google Talk has better Video Chat quality. If you use Google+ Hangouts (Group Video Chat) are free. Skype Charges $9.99 a month for that ($4.99 if you pay a year up front). It doesn't have an option to Auto-Start on device boot so unless you run the app you won't get Notifications for anything - This is true on both Windows 8 and Android, and I'd assume Windows Phone 8 as well (in order to get it to run in the background, you must first start them app and then home out of it). On Android, the app is killed in record time if you disable the background notification - at least on my phone (1GB RAM). File Transfer is beyond slow and I've had files get hung up for over a day until I cancelled the transfer.
The Facebook Chat in their Desktop app is almost unserviceable. Can't send messages to Offline or Mobile friends, which makes it useless as most people use FBC from their smartphones (most people I know, at least). All their desktop clients are AdWare, and are quite... abusive... about it (close an add in the buddy list, it will pop another one up almost immediately) and their UI design leaves much to be desired. Microsoft should immediately redesign the Skype Desktop (and RT) app to look exactly like Lync, IMO. They need to give more emphasis to VoIP/IM/Video Calling than Paid Services. It puts a lot of people off.
Also, a lot of people refuse to use Skype because it puts your User Name in a world-wide directory for everyone to see.
The only reason I see to use Skype at this point is to make cheap voice calls over a data connection when reception isn't there, and that's free if you rack up some Bing Rewards and use the Points to purchase some Skype Credits, assuming you aren't a heavy user (with Rollover Minutes, Unlimited Mobile to Mobile, and Share Everything plans here in the US almost everyone has Unlimited Minutes when reception is present).