Thought he had a good game last night and if im not wrong that's his first real run out consistently as a midfielder for a while, he's played little cameo's but most of his appearances have been as a CB in pre season and i believe last season with Unsy he was mainly used out of CB aswell.
There is 2 types of Besic imo, the Besic that starts a game tends to be a bit more level headed with the occasional erratic challenge when he feels he has not made a tackle that could cost the team, then there is the Besic who comes on late and is hell bent on doing whatever is needed to hold on to the game and that causes him to be far more reckless. The few times he has started his temperament seems to be better than when he has to get up to the speed of the game.
One thing he does have though that no other holding mid in this squad has is an ability to spot a pass behind defenders, couple of times in the 2nd half he played some beautiful balls over the top in to the channels.
This is just my opinion as well but i felt he complimented Schneiderlin more last night than Gueye, Gueye is still my preferred option but there seemed to be a better understanding between Besic and Schneiderlin perhaps because Besic seeks the ball out more than Gueye creating more space for Schneiderlin.