I have used Skype since it first saw the light, many years ago. I have it installed in my computers and gadgets. I use it all the time. In my PC at least once a month for intercontinental chats of about 1-2 hours of length.
Skype for PC is one of my favourite desktop apps and I am mostly happy with it. The quality of the sound is usually very good. Nowadays, I rarely get return and delay sounds and the line rarely drops, something that happened quite often in the past. In the last year, using this app at least once a month, I have had a bad experience, just once.
My main problem with the app is for voice+audio chats, as it is a pain in the butt: with frozen images or very slow movement images or very bad quality image. I don't know if it is related to my Internet carrier or not, but it is most annoying. The result is that I don't make video calls any more unless when these lasts for a minute or two.
Skype's interface for PC is a bit outdated, not clear enough and not customer friendly enough. The home screen should clearly show the options and ask you which one you want to use: voice call, video call, written chat alone, send photo and/or doco, plus the contact list on the side bar.
My account is totally private, only close friends and family are there, I cannot be found by name or email. Yet, sometimes I get requests of people I don't know, spammers, I guess, so I would like that scam to be out of my house and the portholes that take them there, totally locked.
I like that Skype asks me about the quality of the sound and call/video call when I finish. At least they care! I think that serves to improve the service and is specially important when I have a bad experience.
I have had Skype in my Android gadgets for a long time, but it is just recently that started to use it for normal phone calls. In a way, Skype for android has more user-friendly interface than the PC version, is very easy to use, very use to add money, and very use to do anything, really.
I went overseas recently and my usual mobile carrier for overseas didn't have roaming. I added a bit of credit in Skype through the app and made my first call using the app. I was surprised at the great quality of the voice call and the ridiculously low money I spent on a 30 minute call.
Skype for Android has grown on my since then, and now I have it for intercontinental calls over the phone at home. It works great every time. There is a free option in Skype that allows you to associate your home phone number with your Skype account, so when you call somebody from your Skype app, they will see just your home phone number in their screens, which is very convenient and useful for me. Of course proper verification is needed for that. This feature works just in some countries, so check if yours is included in advance.
Skype on the Go is another feature that you can use in the app. It could be great, but it is just an emergency feature for me. The good thing is you can call from your Skype add without the need of having internet but, on the other hand, you need to call an assigned local number to make the call through it. So, it is OK for an emergency, not for my normal calls. This feature works just in some countries, so check if yours is included in advance.
If their fees were cheaper, I would certainly pay for my own Skype number and use the app for phone calls all the time, but I don't think the yearly fears for owning a Skype number are reasonable.
