From a personal point of view, (but aren't they all), I would ignore any multi that would take longer than 10 minutes to complete. Anything more than 1 extra stage from a TRAD cache and I'd not bother. But that's just me.
If cacher A wants to place a 20 stage multi, there will always be a cacher B to go look for it.
I expect a caching status quo on multis as they currently stand.