We present predictions based on the heavy quark expansion in QCD. We find SU(3) breaking in B mesons suppressed in the framework of the HQE. B_s is expected to have the semileptonic width about 1 higher when compared to Gamma_sl(B_d). The largest partial-rate preasymptotic effect is Pauli interference in the b-->u ell nu channel in Lambda_b, about +10 exceed that of B_d and may turn out to be the smallest among stable b hadrons despite the large mass. The underlying differences with phase-space

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... models are briefly addressed through the heavy mass expansion.