Guru isn't that bad, it's possible to get GURU in about ~3 months if you get 1000 XPER a week so about 150 opinions a day, which is possible if you don't use the live feed much and you use the question feed to find new unanswered questions.
Or you can become an editor and get tons of XPER from writing myTakes.
It took me a while by the way, I don't get the luxury (time) of writing 150 opinions a day anymore nowadays :P
All depends on how often you post and what type of posts. Being the first one to post gives extra xp, asking questions that get lots of responses, choosing mho, writing takes which get featured, and signing in everyday, all grant xp.
I've been here since July 2014 and I'm still not a guru yet, but I'm 500xp away. I sign on every day but only post 5-10 opinions.
I have been on GAG almost two years very soon but it only took me ONE year to be a GURU. The kind of job I have in helping the elderly in their homes as a nurse aid, it enables me to be here as much or as little as I want. I am Working towards Master here now in helping Others on this end. Good luck and Happy Holidays. xx