Yes, well worth the money. I've had the lens for almost 4 months and have been very satisfied with the results. It's fine (for me) as a walk around lens since I prefer close crops / fill-the-frame shots. The weight is fine too, once you get used to it. My only two complaints are: (1) it's not wide enough; and (2) it can attract attention, especially with the lens hood attached.
If you are shooting at night, you should be using a tripod and probably shooting at slow shutter speeds. If you are using a tripod, the IS on the 24-105 is irrelevant and should be turned off in any event. The larger aperture size on the 24-70 means that you can (1) shoot 2x as fast on the 24-70 than on the 24-105; and (2) get more significant bokeh and thinner DOF.