Long-channel effective mobilities as well as transfer characteristics of a 32 nm single-gate SOI and a 16 nm double-gate (DG) MOSFET have been simulated with live different Monte Carlo (MC) device simulators. The differences are mostly rather small for the SOI-FET with quantum effects having a minor effect on threshold voltage due to the lowly doped channel, while the two multi-subband MC simulators show some prominent deviations in the case of the DG-FET. High-K mobility degradation by remote phonon scattering (RPS) in free carrier MC approximation leads to smaller performance degradation compared to multi-subband MC with remote Coulomb scattering (RCS) and RPS, but requires further investigations.