This is a little different from the OP's question, but here goes.

I currently have DL Gold status through a combination of credit card MQMs and flying. If I really make a run I could probably hit Plat. But alternatively, I could let miles roll over and start 2013 pretty close to Silver.

Next year, with some effort, I could probably get up to Gold or even Plat (depends on how much business travel I have, but I could probably get to Gold again just on personal travel, maybe with a MR or two).

But I've been a little annoyed with the difficulty of redeeming DL miles. So I'm considering switching programs. Here are my main options:

1) Roll over ~20k miles on DL this year and make a run for DL Gold or Plat next year.

2) Make a run for DL Plat this year and start over at close to zero next year on DL. If I'm back at zero, I can try to make a run on another airline. I can almost certainly hit low tier and maybe mid tier.

I'm in NYC so any area airport is fine for me.

I most value upgrades, and then E+ seating. Other things (priority boarding, no checked bag fees, etc.) are not important to me.

So should I continue on DL, or is there a good case to be made for switching allegiance? One thing that keeps me from switching: I don't fully understand how upgrades work on other airlines.

Thanks!