Yeah, he seems sound but he also seems like someone who could say 'Non!' very firmly & mean it
he also seems to have a neoliberal rather than a humanitarian approach to immigration though; ie 'it's good for the economy' which is not ideal but might just be the best sell tactic I dunno
he seems quite keen on EU wide tax & wage integration as well (to answer @blueturtle a bit better - he did mention economic position) which could be absolutely great ...or could equally be absolute poison.
Maybe the idea of an EU imposed minimum wage is what has May running for the hills (though I doubt it would be set higher than current UK min wage)