I am currently using the stand-alone Arduino IDE to code for an UNO.
Whilst not a fan of C being a physicist Fortran fanboy I do think the Arduino IDE is a very nice piece of code that makes my newbie life much easier - Brownie points to the coders, thank you!
However ... for a general user is there any merit in using a 3rd party compiler, possibly at the end of development. I believe that gcc can cross-compile for Arduinos. If one ramps up the optimisation level is the resultant code significantly faster/smaller.
More curious than anything else but just wondered if this was a common thing to do.