When comparing Skype vs Disa, the Slant community recommends Disa for most people. In the question“What are the best messaging apps for Android?” Disa is ranked 14th while Skype is ranked 33rd.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Easily connect with others due to how popular the service is
There's a good chance that whoever you're trying to reach has Skype already set up and familiar with it, avoiding the hassle of installing and getting to know new software.
Pro Screen sharing
You can show your whole desktop, a select part of the screen or a specific window over Skype.
Pro Cross-platform
There's software for Windows, Mac & Linux and apps are available on iPhone, Android, and Windows Phone.
Pro Group video for free
You can hold video calls with up to 10 people.
Pro Available on Linux
A stripped down, minimalist version of Skype is available for Linux.
Pro File sharing
Skype allows you to send any files (MP3s, images, text, etc.) by simply dragging and dropping then in the chat window making it simple to share things with colleagues.
Pro Cheap fixed phone number
Starting at $5/mo you can get a Skype number.
Pro Send SMS and make regular calls
With Skype Credit bought or a subscription, you can send SMS and make direct calls.
Pro Group chat with archive / records
Pro Powerful 1:1 chat and also group chat
Pro Does what it's supposed to do, without bloatware
Pro Open source plugin API
Everyone can develop their own plug-ins.
Pro Easy to use
Disa is very easy to use and has an open source API, so many new services will be added soon.
Pro Customizable notifications
Ability to set different notification sound/vibration/led based on the plugin.
Pro Unified conversations
Ability to merge conversations from the same contact on different services.
Pro Friendly developers and generally good G+ community
Fast, decent replies to questions, even if they've been asked before.
Pro Many requested features
The developer team does actually listen to the community and adds requested features.
Pro Pushbullet support
Disa works great with Pushbullet, allowing you to answer from your PC.
Pro Many languages
Help and support in many languages.
Pro Disa takes privacy much more serious
Currently, the Disa team knows less about you than the website you're currently visiting.
Pro Great material design
With color-changing design with custom colors for each service.
Cons
Con Plagued by bugs on all platforms
Crashes and other bugs are prevalent on Android, Windows and other platforms.
Con Subpar video quality with more than 5 users
Skype has significant problems with multiple users and video quality. Skype recommends that a max of 5 users group chat as video quality is severely affected. Even webcams tested with other chat services showed lower quality when used with Skype.
Con Not a feasible alternative as a professional team chat
Missing key feature such as centralized mgmt, centralized billing, data retention policies, ...
Con Poor quality when screensharing
It is not possible to manually set resolution or bitrate, and Skype often defaults to a resolution so low that text is unreadable. It is also not possible to transfer control over mouse and keyboard.
Con Slow filesharing speed
Con Owned by Microsoft
Con Obnoxiously large ads
Ads take up over 25% of the usable space.
Con Poor Linux support
The version available for linux users is quite outdated, and does not support some of the newer functionality, such as the free group video calling and screen sharing.
Con Requires both ends to be online (if neither end is using a cloud-enabled device)
Messages are sent and received only when both ends are online, if neither end is using a cloud-enabled device. In this case, if you are online 9-17 and your recipient is online 18-3, messages will never be delivered.
Con MIcrosoft (Skype's owner) actively assists eavesdroppers
On the other hand, if you lose your copy of one of your conversations, you may be able to get a copy of it from your government with a little bit of luck and a public records request.
Con Doesn't support most messaging apps
Con Disa doesn't follow the Google Design Guidelines
Hamburger Menu/Navigation Drawer (Side Menu):
https://www.google.com/design/spec/patterns/navigation-drawer.html#navigation-drawer-contentNo Animations:
Empty Pages/States:
Maybe a Launch screen?:
Con Does not support Google SMS
Con Closed source
Disa is closed source, so the development speed is capped of their team, no external developer can help or add features that are not on the route of the team.
Con Doesn't support WhatsApp at the moment
Con Attaching pictures suddenly failed; no working solution.
Con Smaller development team leading somewhat slow implementation of requested features
Though the main development (framework, etc) is moving along fine, things like quick reply and sending multiple images at once should've been in quicker.