I'm doing a basement now that had 34 recessed lights on the drawing, but someone failed to notice that little stuff like ductwork, pipes and joists were going to be an issue. It looks like we're going with the Seagull 14600S 5"-6" retrofit kit which fits in a 4" round deep box or a 4" square deep box. They put out a very good amount of light, but they do protrude slightly. I also used two of them together with two Juno ICLED20R and five WAC HR-LED87 at another job. The 3k color temp between manufacturers doesn't match perfectly, but the customer is happy.
Some manufacturer needs to design remodel and new work housings around an LED driver and module instead of retrofitting them into existing housing designs. It's stupid to need that much space in the ceiling. For pucks, the new -87 series are great - they use a standard CL2 driver that's dimmable out of the gates and they're easy to install. It's a shame they're not rated for drywall ceilings.