I do rural inpatient and outpatient. Just like any other practice in rural areas there are some limitations to what you can offer. You likely won't be managing baclofen pumps. There will also be less SCI and TBI patients compared to a larger city if you wanted to sub-specialize or manage these populations. There are usually plenty of options for pain management, injections, and MSK depending on what you want to do. On the inpatient side you will likely treat more cardiac/pulmonary rehab, debility, ortho (general rehab) and stroke populations.
I recommend making a profile on practicelink and searching for PM&R jobs. You will find rural employment or small city employment opportunities to just get an idea what is out there (always good to plan ahead). Most people do not want to take rural jobs and the jobs are harder for recruiters to fill. Usually better compensation and higher sign on bonuses. You will also be more likely to have student loan repayment in rural areas if signing on with a hospital network.
Usually, pay and hours can be anything you like. How busy do you want to be? If you do inpatient only then you want about 16 patients per day on average to make a decent living (some rural centers will be too small to have that high of a census all the time). Adding outpatient will give you more income and ability to widen your scope of practice. You may also be able to add on SNF consults or LOCUMS work in a nearby city if you needed more patients.
There really doesn't have to be a difference in how a day looks for a city doctor or PM&R doctor, it just depends on how busy you want to be. When you start a new job you will have to market yourself and get referrals and earn a reputation. This takes time, but eventually you should be able to get as busy as you want to be. You may, however, have to travel some for rural work depending on where you work between different clinics. Same thing for lifestyle.