I'm only a VERY occasional user of FB, and mostly to read what my distant family members are up to, although I do 'like' a few business pages as well. I do use Twitter a lot, and more and more I'm using G+ as well as a way to connect with other photographers. I like the fact that G+, like Twitter does not require a 1:1 relationship; I receive information from those whom I'm interested in and anyone who wants to can subscribe to what I post. I also like G+ 'Circles' idea - I have a circle for Photographers and a separate one for member of my local Photography Meetup Group. One can post to 'Public', to specific Circles or even to specific individuals. I've noticed FB has co-opted some of these ideas as well. The G+ Huddles (group video conferencing) can also be fun.
Should LuLa get onto G+? It's moved beyond personal accounts now and opened up to businesses. It doesn't have the 140-character restriction of Twitter, and there's a place for posting images and such, but much of this is covered through the 'What's New' page. Comments are covered through the forums here. It's another way of 'advertising' the site, and from my (somewhat limited) experience there's been very little of the 'complaining' type. One can also block users and lock comments for a particular post. People who are on Google+ include Joe McNally, John Paul Caponigro, Scott Kelby, RC Concepcion, Tom Hogarty and Bryan O'Neil Hughes, to name a few. In their own way, Google is working to amalgamate all of a user's experience under one banner - GMail/Contacts/Calendar/etc, Google Maps, Google Chrome, Google Documents, YouTube, Google+, etc. They may be shooting themselves in the foot a little in that some new web ideas they have ONLY work on Chrome, for example (remind you of a particular European camera manufacturer?)
Mike.
P.S. There's a free G+ name shortener at gplus.to - mine is
http://gplus.to/wolfnowl You can also find me at @wolfnowl on Twitter