That's not the exact question to be asking. It is about the overall focus.
As a Nurse Practitioner you will choose a particular population - Adult, Family, Peds, Geriatric, etc. and you will be educated in overall diagnosis and treatment of that population. So it more about learning a broad range of things that may affect that population so you will be prepared to diagnosis/treat.
A Clinical Nurse Specialist chooses a specialty such as Cardiovascular and you are educated in basic diagnosis and treatment of that specialty. These jobs are generally in a hospital setting and many CNS nurses are trained to do specific specialty procedures or to treat highly specialized populations such as patients having diagnostic procedures such as Cath/PCI (you would scrub and help do those procedures which nurses usually don't do) or actually diagnosing and treating post-CABG/CCU patients (above the level of the CCU staff nurse).
It sounds like you need to do a little more research in the jobs available in your area and the education of the two types of nursing masters programs so you can see which one is a better fit for you.
I believe there are also some issues that vary by state pertaining to coverage of services provided by one versus the other from third-party insurers. I imagine you would be informed of that if you were to attend school in the same state where you intend to practice, but if not, then it's particularly important to do your homework on this before you enroll in a particular program.
In addition ... many CNS's take jobs that involve evaluating and upgrading the care provided by a certain facility. For example, if they work with the oncology population, they may look at the care those patients receive and develop projects or new programs to improve the care provided by the facility ... be the change agent that brings in the latest treatment approaches, etc. Some CNS's also go into program coordinator positions or research positions. Other CNS's go into Staff Development roles and do staff education ... or take positions as faculty members at nursing schools.
The CNS role is a good role to enter a wide variety of positions as it provides a broad foundation of advanced nursing knowledge. While there are not always a lot of jobs labeled "CNS," ... people with that educational preparation are often tapped for roles for which there is no specific MSN program. Through job experiences, certification, workshops, an elective course or two, etc. .... CNS's carve out a career path for themselves that don't necessarily fit a narrowly defined, single CNS role.
Research the roles of each in your state and then shadow one of each. In most states, CNSs do not have prescriptive authority, but NPs do. Many CNSs do staff education and are the "go to" person on the unit for questions about procedures, the best nursing practice, etc. Although I want to be an NP b/c I want to see patients in an outpatient setting, in my time in nursing school and now as a new nurse, I have come to greatly appreciate the role of the CNS and admire what an amazing resource they can be for the nurses.
My aunt is an acute care clinical nurse specialist and works in a CCU/CVICU. They also have acute care nurse practitioners. In that case, where the specialty is the same, what's the difference in training? I know my aunt cannot prescribe and her badge still says RN but has MSN after it.
NP without question. An NP can do the job of a cns but not vice versa
Many would disagree with that. NP's may legally be able to perform the functions of a CNS (because most CNS functions do not require special licensure beyond that basic RN license) ... NP programs do not typically include the depth of content in CNS functions for an NP to do them well.
Take 2 people. Send one to NP school and the other to CNS school. What do you think the CNS students are doing while the NP's learn medical diagnosis and treatment skills/protocols? The CNS students are learning the skills and knowledge that help them perform CNS functions. I have seen many NP's flounder in CNS roles because they don't have those skills.
Both the NP and the CNS have advanced education and specialized skills. They should respect each other and not assume that they can do each other's jobs without having studied to acquire the necessary knowledge and skills particular to each role.
To think that you can do someone else's job without any education or experience in that field is disrespectful.
Sounds like advanced practice nursing is too niche specific.
In some respects, you are right. It was less niche-specific in the olden days (20-30 years ago) and there were some advantaged to that. That's why I have been happy with my CNS education. It prepared me for a wide variety of roles -- just not the NP role.
However ... the whole idea of graduate education is to become an expert at someting -- and that requires at least some degree of specialization. The more expertise you need for your job, the more you have to focus on that one thing and "let go" of your competence in other fields. No one (or very few, anyway) can be an expert in everything.
That's why I always advise young nurses to really investigate the different career pathways in nursing and get a little experience in different aspects of nursing practice BEFORE they make a huge investment in graduate education. It's a shame when people invest a lot of time and money going down one path only to figure out later that it was the wrong path for them.