I fly for a major cargo company. I think the lifestyle is good for some, bad for many. Yes there is great money to be made, but it will take years to get there. In addition, you have to really have a passion for flying if this is something you choose to do and want to make it to the majors. The low starting pay, bad hours, financial investment to get going, and stress really take a lot of fun out of it so you better enjoy flying.
A couple of things to consider: First, heath. Before spending a dime on flight training, I would recommend scheduling a flight physical with an FAA certified doctor and get a First Class medical completed. You will need a First Class to fly for any Part 121 air carrier (read regional or major airline). If you can't get a First Class or are not able to get waivers to get the First Class then your trip is over before it starts. Keeping this medical current is mandatory until you retire at 65. Trust me, this is not something that everyone will be able to do even once they get to the airlines. If you lose your medical, you are out of a job. Period.
Second, family. Everyone's circumstances are different, and yes you can make a good living providing for your family doing this; however, you will be gone ALOT. Lastly, many marriages will not survive this career. There is even an acronym for it, called AIDS, or Aviation Induced Divorce Syndrome. I know way more divorced guys then married ones in this career. If you are single though, well then the world awaits....