Ultimately you are best demoing the mojo, even if that is through a friend of yours who has a mojo.
The nearest opinion that I can give, is that I have a mojo and most of my listening is done though a pair of Beyer T51is. They share the Tesla driver technology used in the T1s.
They are my favourite headphones to use with the Mojo (my other pairs are Grado GR80, Sennheiser SE598SE, Beyer HD770 Pro, which are not mean performers themselves, but cannot quite match the treble resolution), and feeding the mojo into a pair of focal speakers sounds slightly dull in comparison. I do question myself as to whether some people would find the T51is 'too bright' for their tastes, and maybe a similar question would apply with the T1s. This is a big reason why it is best for you to demo the sound, if possible.
I was tempted by the T1s, but I chose the T51is, as the cheapest way to explore the Tesla experience - I do not regret buying them for the mojo - but this is just my opinion, so please demo yourself if at all possible.