I'm going to add my take here and experience about the airlines in my year flying 121.....
I am currently flying for an airline and am not thrilled with it. What I have experienced is there are some good things and a lot of bad things with this job....with nothing inbetween. Great view and the speed is high on my list, but that is about it. Reduced rest, time spent away from home, lack of physical activity, and periods of just doing nothing is a killer for me.
I can't see myself doing this career forever. This job definitely ages you faster and staying healthy is a constant task to be had. Talking with guys who have done this job longer than myself brings more of the same opinions and experiences; Divorce, fatigue, boredom, burnout, and obesity are things I hear from senior people in this industry.
Don't get me wrong, I do love to fly....but flying an airliner is easy. I would say I am more of a manager and a button pusher. I watch the plane fly....that's about what this job turns out to be. I feel the ERJ that I fly requires almost no skill....I felt more challenged flying GA aircraft than I have flying a transport category jet. I also despise the 4 hour airport sits between legs....there is alot of hurry up and wait which feels unproductive.
I'm going to be pursuing my masters degree here shortly and take up flying as my hobby. While I am still very passionate about flying, I am not so much passionate about the airline career. I find instructing and sharing your love for aviation with someone else who has the same pasison is the most rewarding. I would love to get a job where I am at home and can instruct for nothing more than the love of it. I have a few freinds who have done that and they love it....and they get to go home every night.
But to each his own....someone has to do this job and I am also thankful for those that do and can tolerate the lifestyle. But for me, I like to ride in the back drinking an ice cold beer and fly my GA planes where I want and when I want for fun.
Good luck! We all need it in this business!