mountain busting will rarely look as 'impressive' as city busting because a lot of mountains are smaller than cities.
that doesn't mean they aren't a lot more difficult to destroy however, as there's a lot of concentrated mass more than anything else. also a matter of terminology here in that city busting rarely tends to refer to just guys who leave a giant crater the size of a city in a single pop, but more of a 'clean wipe' of it. mountain busting doesn't have much to wipe besides the mountain. >_>;
but really, the end result is that it's much easier to wreck a city than it is a mountain due to how dense it is. yeah some exceptions exist - obviously a larger city vs. a small mountain won't be the same - but you'll usually find the case is that mountain busting > city busting.
from what i remember though soifon wasn't exactly with a tendency to wait anything out. bleach character yeah, but she prefers to immediately 2HKO if she can. partially because she hates popping out the bankai.
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The King Wang.
Listen up Urinal Cake. I already have something that tells me if I'm too drunk when I pee on it: My friends. - Colbert.