Well, just got instant-approved for a Chase Sapphire Preferred card. First post here, just wanted to share my experience because I did a good bit of lurking before I applied. My average FICO score is 670. I received my first credit card 6 months ago, when I got my first "big boy job" at 23 after college graduation. It was a VISA with my local credit union with a $750 limit. Last month I had the limit raised to $2,000, and this month I decided that I might as well be racking up points and I decided in a fit of vanity that a metal card would be really nice. I make around $85,000 gross, so I'm guessing that is the only reason I was approved with such little credit history and a score less than 700 (and didn't even have to call the backdoor line). Also, I was approved for CL of $8,000.
Thanks to the community for the helpful information--I look forward to contributing more in the future.