PR system was ended by google some 17 months back. Their is no pr update now so forget about pr, concentrate of alexa rankings and moz rankings.
Google trying to change the tracks its true google have kinda monopoly but my opinion still page rank exist so Alexa will be Rank and will be continued so with alexa paid subscription you will get more info how people rank on search engine even google not support pagerank,,so why worry about pagerank try to show up in 1st page,ha ha 1st page still exist ,same thing