The other thing to mention here is the licence costs.
With GameStudio you get a royalty free lifetime licence that also includes free upgrades.
With other engines (Not all) You have to pay royalties after so many sales/profit margin or even yearly.
I think Torque is like this.
You may even have to pay for upgrades.
Also GameStudio is constintly being improved.
Just have a look at the Beta Version or Forecast links found top left of the page.
I mean lets face it. Even if you are an indie. That guy that buys games like UT for its graphics laugh at RPG Maker. But they also laugh at gamestudio, unity, torque, etc... because in comparision it really is not a whole lot. Then again graphics aren't everything (if they were there would not be an indie scene).
That's what shaders are used for. GameStudio has lots of shaders available.
The other thing to mention is, You can also use plugins to customize your game with the Plugin SDK.
Or The engine SDK if you want to add more customized features to the engine there are limitations,
for users who don't own the PRO version however.
But as suggested try before you buy!
Good luck and all the best to you.