For me, the choice is easy. I had the 24-105 when I first bought my 5D3 and it was tough to get those "wow" shots. Also, it always seemed like I needed an additional ~30mm on the tele-end to really make the range useful for an all-in-one type lens. The image quality was on par with what you would expect from an L and the weather sealing survived the New England blizzard last winter...but the extra (albeit limited) reach over a 24-70 f/2.8 just wasn't worth it.
The image quality of the Tamron is superior, the AF speed is superior, the IS (VC) is superior, the f/2.8 gives fair low-light capability and better bokeh. Considering you have an 85, 135, and the 70-200, I can't see what the 24-105 will really add for you. If you are looking for an all-in-one lens, with great image quality, to cover wide to tele focal lengths for travel purposes...join the club. The 28-300L comes to mind but it's expensive and the image quality might leave you slightly disappointed.