Interesting link, MaxF. I found this very interesting:

"The company launched support for the latter two platforms (Wii, and iPhone in addition to PC and Mac platforms) in 2008 and also tripled its userbase. The developer more than doubled its staff in the past year as a result."

So it pays if you support more than one platform. Very interesting. But I also read that most of the Torque users are PC users even if other platforms are available.
This also means that many PC hobbyists are there at the market and could switch to Unity if it is available.

I think Unity has some weaknesses (e.g. scene management, no source code), but the tools are probably the best at the market and this helps to get fast into it. I don't know about the scripting learning curve.