This guide is OK for guiding you through each of the chapters but I found it lacking in some areas.
It describes all the weapons and enemies you will face and help for defeating the bosses etc. and has a nice style with important notes in coloured boxes so the stand out from the rest of the text.
However, I have found the walkthrough missed some very important information, such as power nodes which are not mentioned which I found on my first playthrough. Things like this make it seem like a sloppy and hastily put together guide. The maps that preceed each level also seem slightly incorrect with wrong icons (ie indicating a stasis recharge where there was a store) and they can be a bit hard to read. I would also have found a list of important items such as nodes, semiconductors, special rooms etc. and where they can be found do you don't have to read through the whole guide to find what you need. Also, it barely seems to deal with the upgrade system at all with little or no help offered on how, what and when to upgrade. This is definately and area which I could have used help in.
Perhaps the most important, and possibly worst apect, however, is that the main walktrough is only based on the medium difficulty setting, so there is no specific help for those that are playing on the harder difficulty settings (hard and impossible), which I suspect would be the case for the majority of people who are in the market for this guide.
Overall, it is a good guide if you just need a basic walkthrough of the main story, but it lacks the depth needed to be of any more use. The ultimate guide, this is not.