Fixed for RC 2 :

• Updated translations for new DRM dialogs, and added TRAN() to region alerts (XPD-6209).
• Removed long function ptr type in event hook, which wasn’t safe for passing string ptrs to the XPLM in scenery hook.
• Fixed C-130 taxi and takeoff.
• Now we don’t clear avio bus bits in plane load. This should fix weird power draws on planes that incorrectly have the avio bus src unchecked but do have a load and have some kind of avio usage on the panel (XPD-6502).
• Art control timeout for run loop set to 5 ms. This prevents missing runways for users.
• Includes art fixes for King Air, Baron & KLAX scenery.
• Fixed random resets of systems in plugin-driven aircraft when AI aircraft crash.
• Fixed max deflection of low speed nose wheel when not using a hardware tiller.
• Fixed automatic cursor selection on new knob manipulators when two of the same manipulator are used in different parts of the OBJ file.

 

http://www.x-plane.com/?article=x-plane-10-50-release-notes

Did they give some love to the built-in ATC in 10.50?

I thought I read a while back they were maybe going to...?

Yes, it's definitely improved, the whole "you're off course" is gone.