Yep, I use something very similar to this and believe it is the way to go -- though I don't ever unclip my bottle when grabbing it to take sips. My string is just long enough to allow the lip of the bottle to reach my mouth and also dangle down a comfortable distance.
Just leave the string attached to the bottle at all times, and whenever you need to fill your bottle up or make it more portable, then you just unclip the biner, fastener, clip, o-ring or whatever you use -- no need to tie, untie, or mess with shockcord. The higher on the shoulder strap the better. You can also always toss the bottle behind your shoulder if you feel the bottle bothers you up front or for when you are going through thick brush.
PS. I should mention that I can not attach my bottle high enough on my Conduit shoulder strap for this to be convenient, so I am currently using a combination of this with the shockcord method to keep the bottle from bouncing around. Looking at the Catalyst though, you should be able to find a mini-clip and o-ring that will attach to the strap clip at the very top of the shoulder strap -- it doesn't look like a mini biner would fit.
I should also state the obvious that you should still carry a light 2 liter platy to camel up when 20-32oz of water is not enough between water sources.