So my Swarovski SLC HD 15x56 binos arrived today. I am super pleased with the choice. I had a chance to really sit down with them and do some glassing both at closer objects as well as out past 1000 yards. We just had a rain shower pass through then some sun, so the atmosphere is about as clean as it gets.
Going back to the original question of carrying these rather than a spotting scope for spotting at matches.... Comparing these side by side with my current spotting scope (Konuspot 20-60x80, cheap scope but with good resolution, I've had it side by side with a Swaro and Vortex Razor spotters several times) my take is that the resolving power of the 15x56's is about the same as the spotting scope on 30 power, maybe pushing 35 power. With the binos you can definitely see clearly at 1000 yards, more than enough to call impacts on steel. Now if you're trying to pick up a 6mm bullet going into wet dirt at 1100 yards or other really fine detail, the advantage goes to the higher magnification.
On the flip side, the binos have a couple advantages over the spotting scope. One is the massive field of view which is super sharp edge to edge. For spotting on a stage with multiple targets it's going to be much easier to have all the targets in view at the same time, and easier to reposition and locate another target. I also noticed that the depth of focus was a LOT deeper with the binos. Near and far objects were more in focus. The plus of this was that you can see more stuff going on in the air between you and the target. Anything with dust/pollen/etc floating in the wind, or light rain, or bugs is a lot easier to pick up since it's in focus and there's a wider view. Could be an advantage for getting a wind call in some circumstances. Not much mirage going on here today, but I think you'll be able to see some with the binos. Probably advantage goes to the spotter though on being able to read mirage.
Handholding will also be totally fine for an initial walk up on a stage where you need to locate and identify targets. Another plus will be that scouting at 15x will be roughly the same magnification you shoot at.
Ultimately the Swaros are just way more pleasing to look through. The experience is immersive and 3D, contrast/color/everything is stellar. The size is compact compared to my spotter (though they weigh almost as much!). Mine came with a Rick Young neoprene cover and I like it, very handy way to protect the binos when thrown into a pack but still easily accessible. I can even leave the tripod mount on the binos with the cover attached.
Anyhow, enough rambling... here's a pic.