Now, here's the controversial part of my post. Last but not least, you will have made it to the big leagues. You'll never have to wonder "What if....". You'll know. It won't make you a better person. You won't be better than a regional pilot in any sense that matters. However, you will have reached for the the brass ring and made it to the conventional top of our industry. That does matter to the person that's most important. You. My regional brethren will take exception to these comments, but they don't know. They'll tell you why it makes sense for them to stay where they are. To a large degree they'll be right. It still doesn't answer the question even most of them want to know. What would it be like to fly for a major? They'll never know and they'll keep telling themselves that it doesn't matter. It does matter. I know it, they know it and you know it. Good luck.
Flame suit on.
Remember the joke: How do you know if there's an airline pilot at the party? He'll tell you.
There's your guy.
Seriously, I saw this thread the day it was started and knew exactly where it was headed. FI never seems to disappoint. The original poster was wise to solicit input from others who have gone before him but ultimately, it's up to him to determin what financial, professional, and QOL factors are most important to him. Trust me, if you leave your ego out of the equation, your life will be much better off in the long run.
Several professionals I flew with at the regional are still there, for a multitude of reasons. One is married to a MD, doesn't have to commute, and otherwise finds his job satisfying. The others remain there for reasons I'm sure you know, being at a regional yourself.
Of course, many of my collleagues moved on to the "Majors" and are quite happy- those few that aren't currently furloughed that is.
Myself? I left the regional (and the airlines for that matter) world for a large fractional company and wouldn't dream of going back. I won't bother to explain all of my reasons as it would take too long and really, you need to have your own reasons when considering a new employer. I will say, that in regards to the list of "improvements/perks" that the poster above listed... true. I've never stayed in better hotels, been treated with more respect, been paid more, been home more, etc.
Do your research and then talk to your wife, your parents (- Dad was a recently retired "Major" pilot who PLEADED with me not to follow in his steps to a major) your kids, etc. Make the right decision for you and don't be blinded by ego.