I think there are varied opinions on him. I think you probably are very familiar with the snarky blogger type view from mgoblog writers but he has done alot of positive things in terms of investing heaviliy in nonrevenue facilities and the student athletes love him. At the bottom of this, I linked some comments I made last week in a thread about Brandon here as it gives a different perspective than the complaining you mainly hear. I think when it gets down to it there are alot that have similar opinion to what I wrote in that link (which is generally positive) and then some very negative opinions (mgoblog writers and the viewpoint that gets the most noise in the press).
At the heart of it, I think Dave has created a much larger athletic program both on the revenue side (squeezing more revenue out of football) and on the expense side (heavily investing in upgrading every single nonrevenue facility and has added sports. He has made it an emphasis to improve the experience of all student athletes of all sports. So I think a fan's opinion of him will somewhat be colored by what they value. If all you care about is football, then you look at higher ticket prices and a subpar record on the field. If you value the athletic program in its entirety, then you put value on softball, volleyball, etc and you recognize that he is improving all the facilities by raising the amount of revenue raised from football.