Trying to decide whether to go for the Delta or PRG. I will be flying next year and I plan on running 80% of my total charges through AMEX. Which would be better?
It's June!!
You guys are harsh..........................
Don't know which version of Delta you have. Obviously, Amex MR points are more flexible and PRG has more ways to earn >1 point per dollar spent. But if you have the high end Delta cards and you fly Delta mostly and you can spend the money, the elite qualifying miles are great to get status. Otherwise, use the PRG.
LIMITS IN CARD DESCRIPTIONS
You should wait until January 2014 and get a full year of history. 
There's no point opening an Amex (especially charge) in March unless it's solely to offset the effect adding another card has on AOAA. Are you eyeing another CC already?!
I have low level status w/ Delta - Silver 
I'll take the priority boarding, lol
I had a Gold, back in the day. Only used points for something lame, like a pen. Rest of them went to waste.
Main thing I liked about the gold was SPG's service, it's incredible. Someone booked me in a hotel too far (not within walking distance as requested) from an event. They did not rest until the problem was fixed. I've never had an experience with any rep who worked that hard to make sure everything was perfect. They even did follow-up calls to make sure I was pleased with the resolution. They called while I was at the hotel to ensure the upgrades were done and a week later to make sure there wasn't anything they could have done better to resolve the problem.
I have the BCP and am ACM on DGF's Delta SkyMiles. At some point, before she downgraded from gold, we got complimentary SPG and they never took it away. I never get to travel these days but like knowing they're there.