I have started worrying about reviewing gigs, after someone asked me to be kind in a review. I was just out for the night, enjoying the music and not being a critic.
A couple of years ago I decided never to review anything that I didn't like. It can be fun to be nasty, but not for the recipient, and I accidentally said something about someone that upset them. On the other hand, sometimes a review here is a person or band's first ever write-up, and sometimes people are very happy about that.
I saw Penetration the other week, and enjoyed them too much to want to write about the gig: just wanted to be there in the moment and love all 360 degrees of it all.