My wife and I have lower tier status on United & American, and we'd like to consolidate travel with one of the "Big 3" legacy carriers to achieve higher status & more perks, but we're going back & forth on which airline best suits our travel needs.

I'm currently a United MileagePlus Gold member. My wife is AA Platinum and United MileagePlus Silver. Chase Sapphire is the travel card we use most (no airline specific cards at this time).

United

• Cons:
  
  • requires connecting in Houston or Denver
• Pros:
• Existing MileagePlus status for both travelers
• Points transfer partner with Chase Sapphire
• 8-10 daily nonstops to Houston, 4-7 daily nonstops to Denver
• 5x weekly from Austin to Frankfurt on Lufthansa for international

American

• Cons:
  
  • requires connecting at DFW, which has become increasingly problematic with taxi times, lack of gate availability, and high susceptibility to weather issues year-round
• Pros:
• Existing AAdvantage Platinum status for my wife
• 12-14 nonstops to DFW every day
• Alaska Airlines codeshare for nonstops to the West Coast
• 2 daily nonstops from Austin to London on British Airways for international

Delta

• Cons:
  
  • Connecting hubs are further from Austin, resulting in longer total travel time.
• Pros:
• We travel to SLC pretty often. Of the Big 3, Delta is the only nonstop option out of Austin
• They seem to be expanding Austin into a focus-city (maybe?)
• 3x weekly from Austin to Amsterdam on KLM for international

Based on the airline-specific info above, which loyalty program makes the most sense as an Austin-based traveler?