Well I too was considering the Tron Antares before I went with the Liquid Gold. Pretty much for the reason of its being it having balanced inputs. There has been a lot of debates on this forum about balanced inputs and if it really makes a difference for a headphone like the Utopia.
All I can say is that in the pipeline of Focal is a Utopia Balanced Amp and a Balanced Cable for the Utopia which was disclosed to me from a reliable source. This headphone does benefit from a balanced output. Having said that from another prospective, that in the direction of upgradability, I would encourage you to get a cable that is balanced so that you do not need to replace the cable should you decide to upgrade from your Tron Antares.
Hope this helps...