I do not disagree. In most types of challenging conditions I have more confidence in SLR AF for getting the shot too. In some others, the ML can actually do better.
A fast-paced and chaotic wedding is not the best place for a 'tog with slow gear. Altho if you're old enough to have shot film and manual focus lenses, you might have to concede that today's ML can actually outperform most of those in most situations. Last wedding I shot was a few years ago and slow enough of a pace that I didn't have to run very often and today's ML systems would have handled the whole day just fine.
So ML is not likely to be adopted en masse for wedding work just yet, not when SLRs are available and adequate and their users are more comfortable with them, but MLs are capable of delivering satisfactory results. Some pro's are actually trying Fujis and other ML for weddings and doing OK with the change.
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They're also a lot lighter, so could be easier to carry around all day as a few extra batteries they need don't weight all that much either. :>
I also don't have any need for the absolute biggest and brightest lenses as that super shallow DoF is not always desireable.
But BIGGER is usually more impressive to a north american audience.