Have 17-55 f2.8 IS, need another good walkaround lens, which of these two?

I also have the 28-135 f3.5 IS kit lens (which I've been using so far as my walkaround lens), and have $1,200 or so to blow on an upgrade to replace this lens. Right now I am mainly using these two lens on my 40D for travel pics.

If I get the f4.0 24-105 IS L lens, I lose 30 mm of zoom (I find I could use more). If I get the wonderful f4.0 70-200 IS L, I lose the mid range 55-70 mm focal distance. What am I going to miss more?

I know you say get the 70-200 and take the 28-135 f3.5 with me to cover that small midrange if I really need to but I plan to leave the latter lens home and only go with two lens when I travel to cut down on weight.

I would go with the 70-200mm and just walk up to or away from (foot zoom) for the 55-70mm gap.

70-200 is my vote. I want it too. I too have a 17-55. I also have a 28mm f/1.8 but I think I'm selling it.

I have the 24-105 and am not impressed by it. If you don't mind carrying around 2nd lens a variation of the 70-200 would serve you well. I had the 17-55 and it was top notch; much better than the 24-105 IMO. If have a couple of feet to move around you won't even miss the 55-70 range.

I say get the 70-200. 55-70 isnt that big of a gap so no need to worry about that and the extra reach over the 24-105 will come in handy

Depends on the kind of travel ... if it's mainly street/city style then I'd go 17-55 IS and 135mm 2.0, perhaps with a tcon as needed, just because A1 quality and isn't white. But the 70-200 IS L 4.0 is outstanding too and a very nice buy if you feel you want longer consistently. Again, takes a 1.4x well. i don't think the gaps in range are that important.

I had the 17-55 f/2.8 and 70-200 f/4 combo on my 40D and having that gap in focal length didn't bother me one bit.