A wire transfer is a little different than an ACH. Some transactions seem to require wire transfer, not sure if that's just momentum or there is some other driving reason for the choice.
ACH never really clears, it just hasn't returned yet.
Big banks will have the money next business day at the latest, Tiny correspondent banks in alaska might be as far behind as an extra day or two.
There's a class of return that's supposed to come within 3 days, (NSF/No Account/Closed Account) that's usually what the banks are waiting for, but fraud related returns can be up to 60 calendars later by the rules.
Also, wires can't be reversed (generally). If that's a good or a bad thing is dependent on the transaction and transactors.