I think it was Adam who pointed out to me the secret of the beer glass strategy for spider removal. The key to it is that when you've got the spider in the beer glass, you can see it, so you know what it's up to, and when you fling it out the door or window, you can see that it's really gone.
Well, the same thing works with a Dyson vacuum cleaner. If you suck up a spider, no more wondering whether it's in the bag, or making its escape back up the tube to seek revenge. You can see it in the canister and assess its threat level before removing it. That alone makes the Dyson worth the several hundred pounds extra....
