Your post exactly matches my own approach.

Interestingly regexen are something of an exception for me. Unless they are fairly complicated I don't use /x.

I've been thinking about this because it is, as you say, the exception. My conclusion is that often enough a regex will contain a short section of prose from somewhere else and it is trivial to paste this in from the other source. With /x one would then have to go through it manually and escape all the spaces or replace them with something else. The problem of course compounds with interpolation:

my $pre  = 'Put the needle on the record';
my $post = 'the drum beats go like';
if ($corpus =~ /($pre\W*){3}when $post this!/) {
    $volume++;
}
[download]

Good luck managing that with /x - far better without. When the regex starts to become too large/unwieldy I just split it into several shorter ones which are then combined which I find helps the logical flow too.

For completeness: the one operator I do sometimes cuddle with operands is the range operator but that's likely a relic from some shells (such as bash) where whitespace around the same construct can cause problems.