I don't take the call. I triage based on the transcribed voicemail. Patients know that off hours I don't call back and may not check from visit number one. People still leave messages requesting refills and what not, and new patients call and leave voicemails--will deal with it Monday morning. I don't really count that as being "on call"...do you? Do you not check your work E-mail on weekends?
On a rare occasion or two I have a borderline freaking out on me off hours, and on very rare occasions I have a patient who needs extra things on a Sunday that's sort of "urgent" (i.e. ran out/lost important meds). I do deal with this personally since this is after all cash private practice. But I know for a fact that if you work for an outpatient clinic situation you do not. This is considered extra and insurance companies do not reimburse for this. (Which is why you can charge extra "membership fee", etc. for it without running into balance billing issues if you are in-network operating in a concierge model.)
Meanwhile, when you are on CL or inpatient, your calls are assigned. If you work at a good place you get paid extra, if you don't you might not, and you might not have the option of getting out of any and your scheduling of vacations, dinners etc. have to be completely around that. I guarantee you my "non-call" off hour coverage work is much much less onerous than any of my inpatient/CL colleagues, since 1) they have to physically show up and write notes, can't be having dinner on a yacht 2) they have to round on patients they barely/don't know. I also have 100% control over when I take vacation, how long I take vacation, when and how I deal with off hour coverage, etc. Whereas the exact nature of your call duties are in general controlled by administrators.