United is a tradeoff: You suffer until you've flown enough to get up a couple of tiers in their frequent fliers program, at which point they're great as their frequent flier programme is quite generous. If you don't fly much, then I'd avoid them too. When you do fly much (and 75k miles a year would get you to Premier Platinum, their second highest tier) it's a very different situation. Not least because you also earn miles at a higher multiple at the higher tiers.