You can't compare their value so simply. Capital One "miles" are fixed value, while the value of an Ultimate Reward point varies greatly depending on how you redeem it. Most fixed value "miles" programs are giving between 1 and 2 cents back per dollar spent, while you can potentially get as much as 8-9 cents back per dollar spent on some frequent flyer tickets.

Example: I am traveling to Singapore next spring, and booked two business-class award tickets to get me there and back. A round-trip business class ticket from my home city of Omaha to Singapore would cost between $10,000 and $12,000 if I bought it with cash. Using my American Airlines miles, I got the tickets for 110,000 miles plus about $150 cash. In most fixed value "miles" programs like Capital One or Barklaycard I'd need between 500,000 and 1,000,000 "miles" to buy that ticket. So in this case the American Airlines miles are 5-10x as valuable as the Capital One "miles"! But for an economy class domestic ticket, the difference in value between the airline miles and the Capital One "miles" would not be nearly so great.