When I first started writing reviews, I would try to get them done as quickly as possible. I would test the toy just a handful of times and try to have my review done within 1 or 2 weeks. As I've been reviewing longer (and a bigger variety of items) I've found more value in taking just a bit longer to complete my reviews.
For myself, I've discovered that one amazing experience with the toy may or may not be indicative of my overall feelings of the toy after several uses. And to the contrary, one only so-so experience with the toy may or may not be indicative of how it will work for me long term. For me, I've found a larger sample size helps me write a better review. Especially with toys that are uniquely designed (like the Fun Factory FOU or the Jopen Vanity Vr4.5).
Everyone is different, but I have noticed a real change in my take on reviewing the longer I do it. I can now write my reviews much more quickly when I sit down to do them - but I try to take longer during the testing phase than I used to.
Mileage, and all that.