In general I use the second form which I guess is because of my C influenced learning. But having given it a second of thought I may switch to using a continue block as it's seems the most natural e.g

while(1) {
    ...
} continue {
    last unless $condition;
}
[download]

There's also the issue that the first form is guaranteed to iterate through the loop at least once which isn't always ideal.
HTH

_________
broquaint