NCC is a 24h a day job when you are on. I work less than 10 weeks a year, but I have a fully supported lab. Many jobs are for 16-18 weeks per year, because of burnout concerns if you work 50% or more, although there are definitely people who do that. In my academic practice, we request the weeks we want for each fiscal year, and can specify if we like doing more than one week at a time. We mostly do 7 day blocks. NCC tends to work more weekends than most neurologists.
The differences between Pulm/CC and NCC are mostly patient population, and the care model tends to be closer to SICU than MICU in many NCCUs because of the high proportion of neurosurgical patients, many of whom are post-op.
Pay is what you want it to be. Critical care time is usually billed in minutes per patient, and is much more RVU dense than office visits, although with office-based procedures and EEG and EMG and vascular reading it gets closer. But critical care people tend to do fewer weeks on service than many outpatient or hospital-based neurologists, again because you are on 24/7, and you aren't getting paid for all of those 3AM phone calls and the endless family meetings explaining why someone's husband won't get to watch their children grow up.