Paradox 3D vs UDK
When comparing Paradox 3D vs UDK, the Slant community recommends UDK for most people. In the question“What are the best 2D game engines?” UDK is ranked 64th while Paradox 3D is ranked 66th. The most important reason people chose UDK is:
UDK has an extremely large toolset that allows creating almost anything without having to use a 3rd party tool or plugin.
Specs
Question Ranking
Pros
Pro Good looking and fast
Looking nearly as good as Unreal Engine 4, but rendering significantly faster.
Pro Straightforward editor
Paradox provides a simple and clean working environment for designing games.
Pro Visual Studio integration
Pro Free and open source
Pro Large toolset
UDK has an extremely large toolset that allows creating almost anything without having to use a 3rd party tool or plugin.
Pro Triple A track record
UDK is an engine used by many big name companies for popular games such as the Gears of War series.
Cons
Con Requires a Xamarin license for mobile development
$25/month for each platform.
Con Superseded by Unreal Engine 4
Con DevKit only runs on Windows
Even though UDK can deploy games to run on multiple platforms, including Mac, it does not feature support for development on Mac.
Con Limits games to FPS
UDK was originally developed for the FPS, "Unreal Tournament", and it certainly shows. While UDK is a very powerful engine, it takes quite a bit of work to make it do something other than an FPS.