I should note that:
1) A lot of major commercial games tell which engines/technology they're using when they start
2) Realtime shadows is not a good idea in general anyway. It's better to bake lighting in almost every (if not every) case. (heard this from someone who works with 3D stuff and would know)
3) Some of those things won't matter at all depending on the game being made.
Yeah, UDK is a lot better engine from the technical side, but it is harder. We're not comparing programs with identical uses. UDK smokes Unity for how great the engine itself is. Unity3D is a lot easier, especially for indies (who are probably working alone). If UDK works for you and you don't mind not having the easier tools of Unity, use UDK. Really though, with anything big like programming, modelling, and doing all the other work for a 3D game, know what you're getting into and make sure you choose the right tool for you! There's nothing quite like putting a lot of time into something then not getting it finished...
Everyone who wants to know what each difference between Unity versions should read this: http://unity3d.com/unity/licenses.html
I've noticed things have gotten pushed more towards "heavy-duty" programming and most people aren't going to get anything made with either of these engines (even as relatively "easy" Unity is). Are there any 3D programs made for a similar level to GM, Construct, etc? I think those should be listed too as more people will find them usable.
Note: I'm not a Unity lover if I'm coming off like that. I just want people to be educated. Besides, we need someone on each side of the discussion, right? That way more information gets out.