It is interesting to note that, on "fairground" comparison, that is if our decoder do not have the benefit of a more compact latticerule representation, it actually perform quite worse as we can see by comparing with the third column of table 1 (at least in term of decoding time and memory usage, while it would still have a very slight edge in term of model score with the selected settings).
the K-decoder is a rather strong baseline, shown to perform several times faster than a previous state-of-the-art implementation in (Heafield et al., 2013).