Speech tempo including articulation rate is often considered as a good predictor in the diagnosis of foreign language proficiency and its comprehension. In this study we investigate various sources of variation of articulation rate such as the L2 proficiency level, individual tempo habits in L1 and L2, and more extensive exposure to native speech. In addition, we also discuss the difficulty of the most informative unit for rate metrics which allows comparisons between French and German. The materials used are French and German read sentences, produced as L1 and L2 speech. In contrast to other studies individual habits of articulation rate in the L1 was only partially observed in the corresponding L2 data (a slow L1 speaker does not necessarily articulate slowly in the L2). The convergence of most French learners to the German model speakers shows the advantage of having additional input for phonetic exercises. The fastest German learners also converge to the rather slow French model speaker.