In this paper two Monte-Carlo simulators implementing different models for the influence of carrier quantization on the electrostatics and transport are used to analyze sub-100 nm double-gate SOI devices. To this purpose a new stable and efficient scheme to implement the contacts in the simulation of double-gate SOI devices is introduced first. Then, results in terms of drain current and microscopic quantities are compared, providing new insight on the limitation of a well assessed semiclassical transport simulation approach and a more rigorous multi-subband model. (C) 2007 Elsevier Ltd. All rights reserved.