Rads residency is pretty variable in terms of call, so you definitely have to check around and talk to residents from different programs. The one thing that I think is pretty constant is the fact that the actual day-to-day work is much busier / mentally tiring than a lot of the other specialties. There's little down time and rads residency requires you to read/learn at the same rate you did in medical school. With a lot of the other residencies (particularly the primary care fields) you learn most of the basics in medical school and you deal with only 10-15 different diagnoses 95% of the time- or just refer out. In rads, you see such a high number of cases per day, that you see more diverse pathology... and while if you are in a big enough practice, you can ask your partners for help with cases, you cannot refer cases out.
In general, the larger the residency class, the better the lifestyle. We have ~8 weekend day calls per year and ~20 short calls (short call is ~Q18 days and long call is Q45). Most rotations are 8-4pm. No call as R1s/weekends off. 2 weeks of night float per year after R1. The more residents, the more this stuff can be divided up. Lots of time for moonlighting and making extra $$. I think a lot of rad programs have ample moonlighting opportunities, which isn't so in other specialties.
But- rads is not like IM where you really only work hard for a few hours in the AM before and during rounds with lots of down time in between. In rads you are constantly working and it is more mentally draining than intern year or other med school rotations i had.