This problem has been on my mind for a while. I decided that I could you a second airline in addition to my beloved US Airways to get elite status on. I'll probably be doing a lot more flying this year and in upcoming years than in years past.

I've had pleasant experiences with both recently. I flew Delta last week to ATL, and even though the flight was short and it was one of my few non-upgraded flights in coach, I was impressed and had a great flight. Then, when I was at the airport after the ATL trip, I stopped by the CO ticket counter. I needed to process an upgrade using dormant FF miles in my OnePass account for a friend as a "gift". The agent did the whole thing in about thirty seconds, and he was really kind. I was impressed that it was at the evening rush hour but CO has tons of staff at the ticketing desk and the line was short.

So, I have limited it down to CO or DL. Here are a few factors that I've come up with:

• I'll probably be logging 50,000 miles or so on this airline. I will make Gold with DL. If I go with CO, I can try to push for Platinum, since it is only 75,000 miles, but will definetely make Gold. I have read on the DL board that upgrading as a gold is easy. What about upgrading as a platinum/gold on CO?
• Delta has a CRC in Tampa. I'm not sure if this is a major factor or not. CO's airside is brand new and is always quiet, so a club may not be neccessary.
• Will either comp me? This is probably the biggest point. Generally I do not like the concept of comping. But I'm not going to fly 50K without elite status this year if I could fly US as an elite (ie in First Class).
• I've picked up both airlines' timetables and both schedules are convenient for me.
• I have heard the CO has outstanding service. Better than DL?
• I'll be flying CO/DL to Europe a lot, especially to Milan. I've heard good things about both BizElite and BizFirst. Which is better?

I need to make my choice by next week, because I have a trip to Milan in two weeks and want to go on my new secondary airline (I decided my current US TPA-CLT-LGW BA LGW-MXP was a bit too much). How do I go about getting comped? I should probably book my Milan trip then too, so they know I'm planning on using their airline.

Thanks for your help. I'll post additional questions on the specific airline's board should I have any.

Thanks,
CP