Good Question
This is a tough question and one I ask myself often.
I feel very qualified to comment as I have worked full time for 2 different corporate operators and at least 2 airlines,mabye 5 depending on how you look at it.
Corporate certainly has more interesting flying to far more exotic places. I have had corporate layovers resembled paid vacations at tropical beach locations, ski resorts, beautiful mountain hideaways or exotic foreingn countries.
Promotion comes much more quickly in corporate and a good pilot is usually flying captain in a couple of months if not hired into the position.
At the airlines this can take years of frustrating waiting.You have NO control over this and are at the whim of managements decisions be they good or bad.
Airline layovers have become tawdry affairs in cheap hotels that I would never stay at on my own dime. Often you see almost nothing of the city you are in as the hotel is just off a freeway off ramp and far from anything of interest.
In the schedules department the airlines have always won for me.
Corporate schedulers constantly bugging me and changing my days off and calling for more flying during layovers is what has always driven me out of corporate and back to the airlines. At the airlines your pre determined schedule rarely changes and the phone does not ring when you are off.
For now I am and airline pilot but may return to corporate if conditions warrant.