Sure, especially the few .pdf's that I have bought. But I'm more tuned into messageboard chatter than the reviews. I find I learn more from peoples discussions and their perceptions of how it will be used in their campaigns. The combimanation of these two inputs helped me to decide to buy several products, some I still use, including Toolbox (The only AEG product I still own) , MMMSWE ( Wanna buy my copy cheap ? - not enough "magical" in the society for me ), Midnight (The second best 3rd party setting published in the d20 era - Iron Kingdoms is number one, Scarred Lands #3 ) , Mutants & Masterminds ( inspired me to drop a couple hundred bucks on heroclix figures), and BoTR ( A great book for helping a homebrewer develop a pantheon of gods from scratch, even if just for inspiration - this book is enjoying just to read. ) There have been several more, but these books immediately come to mind.
As far as reviews go , the 1-5 rankings have almost become completely meaningless IMO. The average should be 3 ( by definition, right?), not the 4 that the majority of products receive ( just look at the list of recently reviewed print products - almost all fours! ). So the content I want from a review would be how the product could be best utilized, what it inspired the GM to use, add, or delete from his game, and how those decisions impacted the playing groups enjoyment. I REALLY don't benefit from detailed table of contents type analysis, or the reviewers impression of art, layout, text density, or price. Not all of the content of a book needs to be covered in a review, just the parts that really made an impression ( good or bad ) with the reviewer. Just look at a movie review. Every aspect of the movie isn't addressed from running length to cinematograpy merits,, just the salient points the reviewer thinks are most important to communicate.
I think everyone should write a review once ( I did mine ! - Reviwer name "BFG" ) and it was an interesting experience that forced me to try and think about what was really important to me about the product I reviewed, and why that might be important to a reader.
-BFG