I can see periodically revisiting a product, to review and see if they stay consistent, improve or worsen. But as noted above, without some level of comparison to competing products, such reviews lose a lot of their meaning or helpfulness, IMHO.

However I imagine one reason we see such repeats in certain blogs is to try and capture new eyeballs that hadn't seen the 1,000 prior reviews of Cathay first or what have you and will think it's something new and interesting (oh by the way apply for this CC so you can experience this too!!!).