We often recommend customers using Microsoft ISA or TMG switch their logging to W3C text file, in order to get the best possible import speed, and also because the text logs are much easier to access from a remote machine (see my previous article on accessing TMG’s SQL Express Log database). Logging to the default MSDE or SQL Express databases also requires more resources in terms of processor utilization, memory consumption and disk I/O.
But there is another advantage to switching to text. They take up considerably less disk space. Here are some figures: