This is actually a great post; I can identify with the point the OP is trying to make. I'm very unusual in the sense that I have lower total time than most tenured 121 FO's, but I'm a Part 91 Falcon 2000EX Captain. Going from Part 121 to Part 91 is probably the best thing that could have ever happened to me with respect to honing my decision making skills.

I'm very fortunate to have a boss that has really taken me under his wing and walked me through his decision making, like someone else posted here. The learning curve was pretty much straight up when I first started (this is my first 91 job). I hope those who are aspiring to do the quick upgrade thing without being subject to flying in conditions and situations that demand good decision making (such as single pilot cargo) pay very close attention.