Upgrades are still usually within a year or so. They are more related to how much time you have, when you get to 1200 they start to make plans.
Most attrition here seems to be FOs heading to regionals, not that many captains are quitting here. The captains are a variety of "lifers" and also guys who are holding out for FedEx, etc. There are also guys who leave line flying to participate in our government contract flying.
I upgraded here and I like this company and this flying. There are some cool pilots here, the climate here is pretty laid back and easygoing. But to be honest I started here because it was the first opportunity I had. I've seen you post alot about us in the past, if I were you I would get on the regional bandwagon, there are some good companies out there hiring EVERYONE who applies so it seems. Our charter operation is kind of in transition right now, and lately most new FO's are on some sort of reserve/company b!tch status for up to 6 months or more in some cases. We are even allowing INTERNS to act as dispatchers and bid trips... so add doing their job for them to the list of responsibilities we have.
Bottom line is that there is opportunity here, but this is the hard way to make it happen. If you want to get time to launch into the 135/corporate/fractional world you are in the right place, if you want to work for Delta, etc then you may want to consider the RJ world.