When the merger between Bingham McCutchen and McKee Nelson was announced a little more than a year ago, leaders of both firms offered a good deal of self-congratulatory talk and engaged in a comparable amount of backslapping.

Bingham Chairman Jay Zimmerman, for example, described the union — through which his 1,000-attorney firm added 120 lawyers and expanded, among other things, its tax and capital markets practices in the key New York and Washington, D.C., markets — as “the right combination at the right time.”