There is a product review site which is very interesting because the have a ranking system which is very easy to interpret. However, I found a problem with their filters (you can filter for products according to some defined criteria). For paper shredders, you can filter for shredders of different speed and you can see that in the screenshot below (highest speed paper shredders highlighted with red rectangle:
Now when I click on "24 ft./min. - 60 ft./min. (9)", this was the result: