Some additional points:
Not just a wider ROM on a few exercises but a much wider variety of possible ROMs. Lots of interesting movement possibilities.
But
DB are not less effective for a basic strength program than BB just because you can load the BB more. The more fundamental problem is difficulty with progressive loading in the strength range of 4-6 reps (5# jumps are too much) and, at higher weights, difficulty with getting the weights into position, grip strength, etc.
So...
As a general rule, the better use for DBs is assistance work in the 8-15 rep range.


