I tend to go with more open lens because of my subject of preference which is abandoned tobacco barns, pack sheds and homesteads and mushrooms. Many times I find that I have to prop my cameras to get the shot inside these structures or in dense foliage so the 2.4 is a better choice for me. I know that IS is supposed to give you 1 maybe 2 f stops but that hasn't been my experience. I've carried tripods which turned out to be a royal pain as most of the buildings are overgrown and many of my mushroom subjects always seem to be in the nastiest, darkest crap growing in the area . I find myself on hands and knees easing through blackberry thickets to get inside. I now carry sandbag shooting rests filled with those polly beads that are in beanbag chairs. I used to carry a bunch of craft mirror tiles with light wire stands. I'd line these up to bounce light into the areas of the mushroom flush but now I carry a small 3 watt LED flashlight and a 14 inch collapsible silver/white reflector as a light source. That doesn't work inside a tobacco barn so those shot ends up being a wide open, long timed shot with the camera on bags many times. If someone made them and I could afford them I'd go with 1:1 lenses. To old to "run and gun" now. I mostly creep and carefully select because I only have so many get down and get ups in a day.
