Usually I am in too much of a hurry and can not try it our right away.
If however a product makes me all happy and impressed me quite a bit i will come back to leave at least some stars as review... I am really bad with writing reviews english still not being my main language if I write like a review i get a mental block being reminded of how horrible writing a book review for my GED class ( because my foreign graduation is not good enough here xD ) anyways back to what I was trying to say.

Some products really really deserve a review and I will maybe come back later and rate them other things just kinda get swallowed up in my HUGE runtime after being used for what I purchased them.

On the contrary I also do not like leaving negative reviews sometimes promos look a lot better then the product but still someone likely put a lot of effort into it and just because I don;t like it does not mean others will not and they should make a decision out of their own expreience and not because someone did not like something.. I do however have asked for refunds before when things are just plain broken and that I would note down in a review.