The function in equation (28) can be optimized using variants of gradient descent, which in practice require tens or at most hundreds of passes over the training data (see, e.g., Sha and Pereira 2003).
log-linear models with a Gaussian prior are likely to be comparable in terms of efficiency to the feature selection approach described in this article (in the experimental section, we showed that for the parsereranking task, the efficient boosting algorithm requires computation that is equivalent to around 40 passes over the training data).