Depends on what you fly as a narrow body fo. If you're just flying pre-constructed trips out of PBS, from what I understand the quality of life is probably going to be better on the wide body side, even with the lowered ability to pick your days and trips. If you use the seniority on the narrow body to pick up broken stuff, either short or long-term turns (depending on your preference) or my specialty, one short flight out, overnight, one flight back, then you can have a pretty easy life.
I will probably never go wide body because the idea of sitting in an airplane for 15 hours when I can fly from DFW to OKC and be done for the day just doesn't make it worth a few extra bucks per hour.
For reference, I usually fly 320 to 350 hours per year, actual seat time. I probably deadhead another hundred to 150 (often in first class now thanks to the new contract), and get paid somewhere between 1,300 to 1,500 hours, plus the 401k.