Well, he played on the best Nocturnus albums and in my ears he did a fine job and played very creatively along with the music instead just hitting beats.
In that sense he is comparable to Pete Sandoval, who is also far from having an top notch technique but gets where he needs to be on devotion and persistence.
And, nothing wrong with his vocals. They fitted better than Emo Mowery's 13-in-a-dozen grunting.
And remember that Mike did both at the same time. Not an easy task I reckon.