When comparing CrossBrowserTesting vs BugBug.io, the Slant community recommends CrossBrowserTesting for most people. In the question“What are the best cloud-based cross-browser testing services?” CrossBrowserTesting is ranked 2nd while BugBug.io is ranked 8th. The most important reason people chose CrossBrowserTesting is:
Can automate tests for Chrome and Firefox extensions using Selenium.
Ranked in these QuestionsQuestion Ranking
Pros

Pro Automate browser *extension* testing
Can automate tests for Chrome and Firefox extensions using Selenium.

Pro Free manual testing for CodePen projects
Put your code on CodePen and you can manually test it with CBT from the "Choose a View menu".

Pro Uses real browsers, not emulators
CBT uses real, physical devices for live (manual tests). Check the pictures on their blog post.
Automated tests use real Android devices (Nexus, Galaxy) and iPad and iPhone simulators.

Pro Community / forum
Only 350 users, likely because the Forum isn't linked prominently in the top nav menu and because it uses a crappy engine.

Pro Record videos
Record videos of a URL in the browser/OS combination manually or automatically via the API.

Pro Screenshot comparisons
Automated screenshot comparisons report differences in layout. Manual side-by-side comparison also available.

Pro Selenium testing
Selenium automation for mobile and desktop browsers, using scripts easily recoded with Selenium Builder.
Pro Reusable components
You are able to group the steps in tests into reusable components to manage and repair them easier. As a bonus, you can see all test flows on a single project graph.
Pro Great UI & UX
A design for a high efficiency
Pro Debuggability
You can run tests and debug directly from a Chrome browser, where you have access to DevTools.
Cons
Con Slow and unstable

Con Not a sponsor of the Selenium project

Con Typos in the documentation
"relavent", "retreive"

Con Can't change physical iOS device orientation
All iOS devices are physical and arranged in portrait mode. Emulators/simulators and Android devices can change their orientation via a button or keyboard combination.

Con Very slightly misleading Selenium examples / documentation
The Selenium WebDriver script examples, by default, don't explain what to put in browser_api_name
and os_api_name
. This leads to an UnknownError: Invalid browser_api_name / os_api_name combination specified
error, if you just copy and paste the script.
Instead, first select an OS and browser combination, and the script wizard will fill in the '?'s for you.
