Ho much use you get out of this guide depends on what you are looking for from it. It's a pretty generalized guide and comes in multiple formats in a zip file so you are sure to find a format that works for you.

It's pretty hard to get a strong feel for the games mentioned in the guide. But I would say that is perfect for telling you the kind of thing you don't want. I would use it as a jumping off point for research. You can eliminate some games outright and by comparing the sample characters get an idea of what system you want to explore. For example, if youa are looking for something that reminds you of AD&D or BECMI you can use teh guide to tell you write away what to skip and what to focus on.

The massive Big OSR Matriix Chart is not very useful if you read this on a eBook like Kindle. It worked much better for me as PDF on my widescreen monitor.

It would be a much better value if it included a more indepth review of the games themselves. In fact, it practically begs for it. The guide makes no qualitative judgements as far as I could see, leaving that up to the reader.

There is almost no discussion of the production values or what the OSR community in general is thinking about these games or which ones are being played or how they are played.

It's a nice beginning but needs a lot of fleshing out to be definitive.