I purchased one about nine months ago and have been happy with it. It is well made and includes plenty of assorted pockets, so it makes a good EDC bag. It does not come with a waist belt, so it would not be good for carrying heavy loads for a long period of time. The water bladder pocket makes an excellent place to stash a handgun and I believe 5.11 even offers holsters that attach to the Velcro that is already in the pocket.
I have also been using a Maxpedition Colossus Versipack which I also like. The Versipack is a little smaller and sufficient for most days, but can fill up quickly if you carry a lot of books like I do. Also, some of my buddies think it looks like a purse, but I am quick to remind them it is a tactical shoulder bag.
Anyway, I really like the 5.11 Rush 12 and think it will work very well for EDC. The Maxpedition line is also nice not sure it’s better, but worth a look just the same.