To me t.The great thing about IS/VR is that it lets me take photos more easily. The ability to use shutter speeds a couple of stops slower than I'd expect is a great advantage. Somewhat limited with shorter lenses though by subject movement. But for longer lenses (anything over, say, 50mm) stabilisation is a great help. The 70-200 stabilised lenses beat the non-stabilised ones by a substantial margin, to the point where I've looked at the Sigma 120-300/2.8 and rejected it because it lacks stabilisation (I'd rather use my stabilised 70-200 with a teleconverter instead). For short lenses I don't see much subject matter in the gab between stuff that you shoot handheld without stabilisation and stuff that's so slow you'd use a tripod. Tourist stuff where tripods are not permitted is about the only thing - shooting inside without a tripod at 1/2s is useful in no flash/no tripod situations.
The places where I'd leave it out are very fast lenses, where you usually want ultimate sharpness and D0F is so narrow that IS doesn't help - the swaying toward/away as I hold the camera will shift things in and out of focus so much that only background is "sharp" anyway (were it in focus...). But then there's the Nikon 105mm macro VR which is quite a nice lens too, and the VR is useful.
Where I'm stuck is that Canon don't have a fast, stabilised medium range zoom. The Canon 24-105/4 is a little unconvincing for me, it just doesn't work for what I do. But if the 24-70/2.8 was available stabilised for an extra $500-ish I'd have bought that for sure. Or the 24-105 was f/2.8 instead of f/4. What I'd really love is a 24-70/1.8 (or even f/2.2) stabilised lens. I'm quite torn wishing they'd release something in that range but then I'd be very, very tempted to dump my existing 24-70/2.8 for it, which would cost $1000 or so. Ow! Nikon releasing one would be no better, I'd then have two Nikon lenses on my drool list (the 200-400/4 VR is the other), and be very tempted to switch brands. Gary is doing his best to convince me not to, however.
I do love the tiny size and light weight of the little primes that I have (50/1.4 and 85/1.
, and I'm tempted by something shorter, I just haven't seen a good lens yet (the Sigma 30/1.4 is a crop lens, the 24/1.4 has quality issues, the 35/1.4 is a little long on a full frame). But add in a few primes like that as well as zooms and the camera bag starts to fill up. I already carry 1.4x and 2x TCs most places, plus one of the primes, adding the other two primes would start to bulk me up big time.