Since the discussion is becoming one of style preferenece, I'll add mine. Dispatch tables are often a suprise to someone reading through code. It's common for there to be only one in a module, if that, so it's good to call the reader's attention to what's going on.
While I might use
$op_map{$op_choice}->(@args);
for a one-off, or where I was using it a lot, for most code I'd do something along the lines of
naikonta's later suggestion, only with some correspondence between the names, as in
my $op = $op_map{$op_choice};
$op->(@args);
This separates the lookup from the invocation, so the invocation is easier to see. It also makes adding a default function easier, as
naikonta already showed.