Rolling the dice is the only thing you can do, its a complete crapshoot. The "opportunity for a quicker upgrade" can fade away in the blink of an eye. XJT had an upgrade time just under 2 years when I started. I'm still an FO after 5 years and 3 months, might upgrade at the 6 year mark. I'd would advise someone to take the worst job offered to them because whoever is the bottom feeder today will usually have a quick upgrade and be the "go to" company in a few years. I realize it is a backwards way of thinking but many pilots have got ahead by doing this.