I seriously don't understand what people here mean when they say he's not consistent. The only thing I can think of is his finishing...
A few pages back, quite a few posters actually noted that once he resumes his goal scoring ways, he'll be back in top mode and that finding the net was the only thing missing (past month).
playing captain obvious, we can also observe that the most consistent part of his game are those where luck plays the least dominant part: ie, his alpha competitive effort, his speed and stamina, and to some degree his dribbling, tackles, duels, fouls won, interceptions, chances created etc...
when it comes to goals, the luck factor is much higher due to the smaller sample size [total shots attempted]
And that's where, like you stated, his results have been the least consistent. The difference between a goal and a failed attempt often being a matter of inches.
Don't have time to look it up now as I gotta pack but if you check his 2015/2016 shots to goal ratio, it's similar to Leo's. Suarez had the best one that season.