As with any criticism of any form of art or media, you will find a variety of approaches. Some reviewer/ees employ humor, others play it straight down the line. The main requirements at ReviewYourOwnBlog is that the review be interesting and read well, and that it seem informative and objective.
Thank you for taking a few moments to browse the reviews. The best criticism is in itself a form of entertainment, even a form of art in its own right. The inclusion of a review here is an endorsement of the review's self-contained merits, but it is not necessarily an endorsement of the blog being reviewed. In many cases, the reviewer/ee him/herself does not appear to be endorsing the blog being reviewed. As with any criticism, self- or otherwise, take with a grain of salt! If the review piques your interest, click through to the blog behind it, and judge for yourself. And if the impulse takes you, join in the fun! Formulate your own thoughts about the reviewed blog in a punchy, sound-bite form and leave your rave, pan, or similar blurb-style "critic's quote" in the comments queue of the review. The reviewer/ee will then be free to take these "blurbs" and post them proudly on his or her blog.