I would actually pay for detailed, unbiased advice!
I think its near impossible to get unbiased reviews for indies because there could be money changing hands in the background. I did subscribe to that other "good" one online and I must say there is a lot of bias and sometimes tongue in the cheek stereotypical views to reinforce what people think about a certain school which maybe totally different to what it actually is.
In addition to the diff you highlight guest43 there are also families which have traditionally done indies and they normally go for certain types (normally public schools) so they dont need any reviews. The majority that need reviews are probably more first time buyers and they tend to go for certain types of schools too a bit diff from what traditionally indie families go for. Its very easy to see at open days who the main target market for a school is.
Even when the reviews are unbiased its really difficult to know if it suits your child. I saw one a while ago with very good independent reviews and it really is what these people say, however it was just not a suitable for my DD and we knew it straight away. I would still highly recommend this school but for certain children so this is why its important to visit the school to get a better understanding of what goes behind the scenes and see what your gut instincts tell you.