The only flaw I see with reviews giving 20 reputation with no option to rate the reviews (something that was suggested several years ago) is people like BFG20k can write poor reviews like here: lvlworld.com...ts/id:1807#n25427
and they get a ton of reputation even if the review is bad. Though I suppose one answer to poor reviews would be to offer to write a replacement. A good example of this was Stonemaze lvlworld.com/review/id:1860
where the original review was essentially this:
It pains me that someone would post a map like this.
Reviewed by Anonymous
I remember I posted anonymously with the handle "$$" (you could check the IP address and see that it's me). I don't really remember why I made posts with different names, but I guess I wanted to make it appear that the map was getting new comments from more than just me at the time. Anyway, as $$ I offered to write a whole new review since I actually enjoyed playing the map in a LAN game with people I know and I was annoyed that that passed for a review. I suppose every map needs at least a placeholder review and finding people willing to write reviews is getting more and more scarce. However if someone writes an objectively bad review, then I think the 20 rep should be revoked from them if it gets replaced by a better review.