It's easy and simple to look at hours worked and conclude that radiology is a lifestyle specialty, but that's misleading. After all, there's a reason why many older radiologists are lamenting the good old days and internists are writing articles about how technology is killing the field.
In the face of declining reimbursements, radiologists have chosen to become more efficient rather than sacrifice income. That increased efficiency was made possible by technology, but other things came with and added to it. Whereas a radiologist might be able to take a few extra minutes to chat in the dining room with other physicians, now we eat lunch at our workstations. An odd or interesting finding might have once prompted a few minutes of research or consultation with a colleague, but now we're increasingly forced to blurt out something semi-intelligent before moving on to the next study.
The increased focus on turn-around time has also spurred greater efficiency. Part of that came from inside the field, where PACS systems made images accessible nearly immediately, and voice recognition software led to self-editing with reports often available within minutes. But some factors were external as well, such as the ED's near singular focus on disposition and billboards advertising less than 15-minute wait times. It has become a bit of a positive feedback cycle, whereby the ability to have a short turn-around time has fueled expectations that it will always be like that, thus pressing us to work even harder and faster.
Also, as recently as when I was a resident, getting an MRI after-hours was kind of a big deal. Now, some hospitals have magnets solely dedicated for the ED. Heck, I used to have to do my own ultrasounds on call because they didn't keep a sonographer in-house overnight. Bottom line is that this used to be much more of a 9-5 type specialty, whereas now it's very much a 24/7/365 field. When I'm on call, I'm in house with the intensivists, hospitalists, EPs, and whoever's in the OR (ortho, trauma, neurosurg, anesthesia, etc.), which is a relatively recent phenonemon for radiology.
So, yeah, we can look at hours worked, and that goes a long way for a lot of people, but it doesn't tell the whole story. For all the reasons above, radiologists are working harder than ever, and I imagine that our increase in productivity (and with it the expectation to produce) over historical baseline is greater than most or all other specialties. That's the downside of working in a task-driven profession. It's also why I hear about so many radiologists squirrelling away money in hopes of retiring early and complaining about burnout.
Obviously, people will define "lifestyle" in different ways, so the OP's question requires a decently nuanced answer. I think when we talk about PP radiology, we tend to think about the individual workday, which is often jam packed with mentally exhausting work. But we forget about the bigger picture, which includes lots of vacation and the ability to leave at the end of a shift without worrying about getting paged. Those are the upsides of working in an efficiently run task-driven profession.
As an aside, the ability to sell one's call is a zero-sum game. For every radiologist taking less call there is one taking more. So what's really being espoused here is the field's flexibility, i.e. jobs that let you work as much as you want. I think you'll find that private practice radiology groups are less flexible than many other fields. There are strong expectations to maintain productivity for the partners, or subset of partners, who want to keep their incomes up. I can't tell you the number of times I've heard a radiologist wish they could work 25% less for 25% less pay, but that's just not an option in their practices.
