Calfee builds a great c/f tandem; ariZona tandems is a one-man operation (so far) and his work is equal to Craig's; however, he does as yet not have the name recognition of Calfee + the ariZona frameset costs $1,000 le$$.
Have ridden both Calfee and several ariZona tandems. Impressed enough with Bob Davis that I just took delivery of one of his custom singles.