Hell yeah! I love reading reviews on comics and stuff, I follow a few formal/informal ones on Tumblr, and a few other sites. I prefer longer, in-depth reviews or criticism, but I may follow people who make shorter ones depending on how the material is handled.
If you want to make a blog dedicated to promoting content you like, go for it! There's plenty of "not so much review, but promo" sites out there, and personally, I feel you have never have too many review/promo stuff. Especially for indie work like webcomics.