IMO, DUI drugs has a worse connotation.
If given the choice, I would plead to a 23152(b) count, before an (a) count.
The sentencing is usually the same, but if the driver was under the influence of meth, etc. as proven by a blood test, then the Prosecutor should add a H&S 11550 charge - under the influence of drugs also -- which means a mandatory minimum 90 days in jail, separate from the DUI.