I think it should matter. The reviewer should say if it was a gift or they paid for an item.
For those starting out, some reviews can be helpful however relying on them can be a problem. I have a ton of stuff here that I find mediocre and yet was highly praised. Not saying they were wrong but just saying it's really a YMMV thing, however there is a big however. Consensus is still very valuable.
After trial and errors, and jumping into hype wagons time and time again, I have learned that peer consensus is much a much more reliable gauge if I am likely to appreciate a product or not. A reviewer is just one person, he has his own experience, his own bias and sometimes his own ego.
It's difficult to pay big bucks for someones ego.
I think the more experiences we gather is almost always better than one. I tend to check out consensus, and after a while in this hobby, you'll develop that instinct that sometimes tells you a certain product is being overhyped or genuinely brings something new to the table.
I once told a friend that I am only shooting myself in the foot by not praising a high value item that didn't work for me. I'm the guy who spent money on it, and if I don't praise it as much I may not be able to resell it easily, but I am not in this hobby to resell. Others have surely enjoyed it, but I didn't. I don't see a reason why I shouldn't share my own personal findings in a forum for us enthusiast.
I understand we all have our experiences, and I have made a mental note on guys that I think are on point in their opinions. I gather all that, even newbie opinions and use that as my guide if I am going to spend again. This is not to think newbie opinions are lesser, but I know for certain many of the stuff I liked when I was starting out isn't that amazing in retrospect. I think experience is more reliable and I value that and earns an extra point when reading reviews.
Reviews are entertaining, and if done right is very informative and helpful, but like with many things in this hobby, your best reviewer and guide is still you. Have a good nose for hype, try a product, be true to yourself, and when you share your reviews in the forums, do it honestly, with integrity while still keeping tact and being polite to the artisan or craftsman. Don't be a jerk, but don't sugar-coat things too much that your message cannot be understood. Not all products are bad, and certainly not all can work for you.
There is no need to sugar-coat things, just do it with tact and respect, and expect that not everyone would feel the same way. If there is a consensus, then more likely that not, it's not you, but it's the product that may need some improvement.
An artisan once offered me a sample with my purchase. I appreciate samples, specially for us non-CONUS, almost everything is a blind buy gamble. I told the artisan I appreciate the sample only for the scent, to help me determine my next purchase but I don't do reviews well, and to be honest I am kind of lazy to do that really, this is a very personal hobby; but if I liked a product I am certain to recommend it to my friends. It's in our nature to talk about things we really liked.
The first time I tried the 6s, I kept talking about it cause I really liked it. Not sure about the makers as of late, but I enjoyed the 6s and I still recommend it. It's great value and performed very well for me.
A trick I learned with blades is that I read threads, and take mental notes on guys that mentioned and liked blades that worked for me as well. I then start to pay more attention to their other favorites, and more often than not, other blades they liked even obscure ones works well for my skin too.
Not always, but it seemed to have served me well. I have hundreds of tucks of excellent blades that I wouldn't even know about if it weren't for these peer reviews.