We are not aware of any mikveh review resource in the US. There are some reviews of Israeli mikva'ot posted on the Kipa website (in Hebrew): http://www.kipa.co.il/mikve/, as well as a checklist of services provided. Another Hebrew site, http://www.mikve.net/, also includes reviews, descriptions, and photographs of some mikva'ot. The Global Mikveh Directory at http://mikvah.org/directory/ does include photographs of some mikva'ot, but no reviews. None of these sites provides comprehensive ratings of all the mikva'ot listed.
Since mikvaot are community sponsored, volunteer driven religious institutions, we would hesitate to review them. Also, women's experiences at and perceptions of mikvaot vary widely. However, we can see how a service including digital photos and basic information about the mikveh might be helpful.
It is usually worthwhile to try your local mikveh first. If it is acceptable to you, you would have a most convenient option and the possibility of immersing on Shabbat. Your input and monetary support could help improve its service.
Should it prove inhospitable, you might try word of mouth. In New York City, personal experiences at the Upper West Side mikveh, the Riverdale mikveh, and the mikveh of Washington Heights were positive.