First, once you reach Platinum should strongly consider buying up to Chairman's Preferred. It will be less than $1,000. You'll get Europe upgrade certificates now, plus another set on March 1. Two sets of upgrades to Germany is well worth the cost.

For 2014, my answer depends on how many miles you expect to fly.

If you foresee 100,000-125,000 miles, enough for high tier on United, American, or Delta, then I would switch. Your program of choice should depend on where you expect to fly. If you're going up and down the east coast, American doesn't look so great, as a lot of their routes seem to connect in Chicago. Convenience, not price, matters for business.

If you foresee less than 100,000 miles, I'd stay with US Airways. Because it has fewer elites, upgrade rates are better at lower tiers. The award chart is competitive. At Gold or higher, there's no phone booking fee for awards, removing one of the disadvantages.