When you see a manuscript that has 10+ reviews do you still post a review?

Do authors of such books generally find the additional reviews helpful from the writing perspective?  And are there any systemic/rankings Book Country benefits to multiple reviews beyond a certain thershold?

I'm asking because so far, I've been reading much-reviewed manuscripts but not reviewing them, and I wonder if I should be.

I know that many people appreciate a fresh set of eyes (myself included) especially if, like Colleen said, there are several drafts and repeat reviewers. The repeat reviewers usually base their reviews on improvement from previous drafts and they have foreknowledge of what comes next. New reviewers are seeing the story for the first time & will be able to find holes in plot & etc. that repeat reviewers might miss.

All this to say that yes, you should post a review if you think it'll help improve the narrative!

Whether your's is the first review posted or one of three-dozen, the only Maria Granovsky review the writer will be able to read is the one that Maria Granovsky posts. So yes, go ahead and post! Your opinions, viewpoint, writing style and critical commentary are unique to you and only you. Why deprive the writer of that voice and critical feedback? I can't think of a single writer on this site who would start a discussion thread entitled: "Too Many Reviews/Reviewers! People, Please Stop!"

PS. If you're worried about your own feedback echoing something other's have said, I would note: (a) one more voice drawing attn to something the writer is ignoring couldn't hurt! (b) you might ignore posted reviews before writing and posting your own; this way you won't be influenced by what others have written, (c) every review I get is welcome and always read with keen interest, whether Review #1 or Review #10+. There is no diminishment of excitement/nervousness/curiosity as the reviews accumulate; on the contrary, one's interest in soliciting further feedback only rises as one modifies the story and posts successive drafts in accordance with constructive criticism already received.  

I can only speak for myself, but I'm sure you'll hear from many other writers on Book Country as well.

Colleen, Lisa, and Carl, thank you for your insights.

I'm beginning to understand the value of additional reviews through my own experience here - and will second Carl's observation that each review elicits the same excitement/nervousness/curiosity as the first one did.