The shutter lag is bad only with OS (Optical Stabilization) mode 2, but you need that only if you end up using very low shutter speeds (1/4 s or so at the wide end), with 1/8 s or faster OS mode 1 works well for me.
Of course no OS is needed at the wide end at 1/30 or faster.
Things start to get a bit more complex at the tele end, 1st because the lens gets almost 2 stops slower, and 2nd because higher shutter speeds are reqired, so at the tele end I'd say OS2 for speeds slower than 1/30, OS1 between 1/30 and 1/125, no OS for faster speeds.
OS1 introduces almost no shutter lag, so you might as well have it on all the time.