Michael after 4 years in the NFL, was pretty much the same player he was in college. Immature, undisciplined, mental midget that couldnt stay on schedule and own his plethora of opportunities that he got to prove himself. He landed in the doghouse at A&M and he did here as well on multiple occasions frustrating Cable time and time again. Michael bottom-line just did not inspire much faith not only amongst his coaches, but the players as well. Once your teammates stand against you and you don't take to the coaching, and continue to make the same mistakes... this team has shown that it will move on no matter how talented you are or how much money you make despite the depth situation.
Thats the feeling I got from the team reading between the lines.
On Collins, he has shown very little at this point both good and bad. However, the team continues to hold onto his talent. I don't know how well he's doing in practice or if the team feels he close to understanding the processes he needs. But if Collins was to translate what he did in college onto an NFL field, he would be solid enough. Time will tell, and he looks like he will get an opportunity to be evaluated. Who knows maybe he's a gamer that turns it on with consistent carries.
To answer the question is hard, in one hand Michael is seemingly more talented, more experienced but he seemingly can't be trusted to do his job. He wasn't good but he wasn't bad just frustrating.
In the other hand, Collins hasn't shown much from the outside looking in, but if he can run the right plays, hit the right holes in the design, and do his job right mentally is that better for the team. I think we all want to see Collins flourish and showcase some of that vision and physicality he showed in college. Time will tell.