And just like everyone else, I'm naturally intrigued with this idea and would totally be interested in receiving a video review on my/our channel, Confidence Crew.
I see that this might be a really successful idea to do reviews on channels, provided you get your own subscriber-base.
If you want my opinion though, I feel that, as a requirement, that the channels you decide to do a review on should be:
A) Channels that take themselves seriously, and are specifically and progressively trying to become better, get more subs, and put out videos regularly.
B) Those willing to provide a shoutout to your channel in exchange. It's not enough for people to jump on your thread and say "Yeah! Do mine!" *cough* for free *cough*.
C) Those that are interesting enough to actually be worthwhile enough to do a review on.
But, of course, its your channel.