I do it the old fashion way... I manually cull. Mind you, since I do multi-row panos, I usually have to pick from a set of panos spanning a period of time. If I have one slightly blurry photo of a pano, then the entire pano is tossed. But it also depends on the time of light. The first few panos (if at sunset) will have a brighter sky vs the foreground while the last few sets will be when the sky is much darker...so have to pick the best "time" - which is usually in the middle. I guess with landscape photos - I generally only ever take photos if I know it will be worth taking. So if the scene has too many distractions, or the weather is not right, I simply don't take any photos. The best cull - is to cull before taking the photo - knowing when not to shoot, IMO :).