For the "exact" predictor-feedback control design, recently introduced by Tsubakino, Krstic, and Oliveira for multi-input linear systems with distinct input delays, we establish input-to-state stability, with respect to additive plant disturbances, as well as robustness to constant multiplicative uncertainties affecting the inputs. We also show that the exact predictor-feedback controller is inverse optimal with respect to a meaningful differential game problem. Our proofs capitalize on the availability of a backstepping transformation, which is formulated appropriately in a recursive manner. An example, computed numerically, is provided to illustrate the validity of the developed results. (C) 2019 Elsevier Ltd. All rights reserved.