I don't think it would be useful. Punting is such a personal thing. We each have different needs and interests.
Conceptually, it would completely miss the point of punting which is individual satisfaction. An aggregation of fan reviews would be like the bestseller lists: I am not interested in E. L. James, I prefer Tolstoy or Guy de Maupassant. I understand the sentiment behind the idea but it would be a fluff-fest for fanboys and indulge a herd mentality which could be open to abuse by touts.
When I see a review on here, the first thing I do is click on the link to see if I would be interested in fucking the WG in question. If yes, I read the review, if no, I don't bother with the review and move along. There is also a voyeuristic element to reading reviews, akin to punting by proxy, which is only satisfied if one is interested in the girl to being with. In other words, if the WG does not meet my visual needs, I am not interested in how good her service is or how well reviewed she is.
A punter can do a search on AW and list his requirements. He can then find a suitable WG in respect of which he can search the reviews on here. This suggestion of a 'top ten' list would be a reversal of that process, and is underpinned by the mistaken premise that needs may be satiated because someone is on a list. Again, because of the personal nature of punting, I cannot see how that could be the case.
In summary: the idea misses the personal nature of punting, would be open to abuse and the utility it could potentially provide is already open to punters searching both AW and here, so no, I do not think it would be useful.