I don't know if this is something peculiar to the DOHC model, but I find that 1st and 2nd gear on this bike to be almost totally useless.
1st gets me rolling, then almost immediately I'm shifting to 2nd, then by the time I'm at 30 I'm in 3rd which has a very wide range of speeds that it operates at comfortably.
To me at least, the CB750 Limited seems very much like a highway cruiser rather than the sporty city bike that the SOHC model is.