Whether you've been writing for years, or are a newbie with your first book, this is the site for you. The critiques are from fellow writers who know what they are doing. There is both a paid and free service, but the critiques are the same for both. The extras are things like as many messages as you like in your inbox.(free people only get 10.) As many critiques as critiquers wish. (Free members only get 3 per post.)
You must critique other's work in order to gain 'karma' in order to post your own.
I have found the critiques I have received most helpful. Knowing the people critiquing your work are other authors is reassuring. I would recommend this group to any author, no matter their experience.