Its a good program, just pick it up and do it even if you can't clear it as co-op. Compared to what the guys in the art program did while I was in college, Marcs program is much more focused on actually producing illustration work as opposed to attempting to get into the "fine art" community.
The classes are very in-depth, I found the anatomy classes to be especially good. He also does several classes on zbrush, very helpful program that is industry standard. Depending on the subject the individual class can reach up to around 4 hours. And several subjects are spread over several classes.
Marc plans to keep on doing the weekly streams and hasn't said anything about stopping, I would assume he would keep doing them as long as he has people coming on, they are good for publicity and he seems to genuinely enjoy doing it.
Don't waste your time on a coop that does not serve the purpose of your intended career direction, given that illustration is all about practice you should either get in somewhere that does what you want and learn there, or something like this and just spend 16hours a day working at it, you would get a lot more out of that then a counselor camp position (unless you want to do that, kids are fun).
But I would say you should really do some looking around on your own for a coop that would be helpful and get you more direct mentor-ship than just the once weekly short burst. You should still do this program on top of other things, but get a useful coop if you can.
And as far as progress goes, This is kinda inaccurate, but I guess 5 months of very low intensity work (1-2 hours 4 days a week Mostly useless) and 1 month of 2-3 hours per day, and now 3 weeks of ~8 hours per day Ive got these images for a gauge of change.
day, I don't know... a bunch?
I hope this helps you. But you really should pick up Marcs program no matter what you do with the coop, its a good program.