I work in Great Plains so I have a little insight into those industrial routes.
23 south of 17th IS used, but at the moment it's not well used at all. It's almost impossible to get a good connection coming from downtown on the 1/MP so that's why I personally rarely take it.
42/49- I assume the 42 is doing okay but I know the 49 has had a massive increase in riders, probably due to the fact you can actually....ride the 49 (no longer every 23-61 minutes!)
58 is doing quite alright
67 always seems to have at least a dozen people whenever I ride it
68 isn't getting the ridership they'd hoped for I know that much, but there are a small amount of people who take it.
147 is starting to gain some traction but on a 30-60 minute frequency and no service evenings/weekends there really aren't many riders you can attract.
148 definitely has less people than the old 23 going to and from Chinook, but I can tell you it is getting used. I always seem to use it going in the reverse peak direction, so I'm always on a near empty bus but the one(s) going the other way seem to be fully seated.
149 is a dead route. It doesn't go anywhere and only occasionally will I see no more than 2 people on the bus or waiting for it at South Hill.
150- I have only ridden the it once, myself and three other people on the bus at 6:30pm on a Friday going towards Anderson. It seems decently used at rush hour but outside that....it's sufficient for a shuttle route.
MAX Teal and Orange seem to be getting decent ridership from what I've seen, I've noticed more people will now decide to take a MAX Teal over a 20 or 9 between MRU and Heritage and between MRU and Westbrook, respectively.