In MOST cases it seriously doesn't matter. Houdans are very rare, most of the stock if not almost all have been bred so much for production and pet value that they're nothing like the breed originally was, honestly, most look like Polish with mottling and 5 toes, so, it's up to you.
I don't have any purebred Houdans right now but I have two Houdan x Polish hybrids. Very alert, calm, but not as friendly as the Polish. Great foragers, great layers. The Houdan behind my hybrids though are bigger/better stock than most, so, my hybrids are bigger than my Polish.
I've got Polish from several sources (hatcheries, local breeders who got theirs from many sources, and also exhibition breeders) and I think they rock. As long as you DO NOT have a small ratio of Polish in a mixed flock of non-crested breeds, they're very strong birds who are very intelligent, super foragers, great layers, amazing fliers, and very alert and aware as long as something is done about their crest in a free ranging environment. However if you live in a dry area, you don't need to worry as much. Out here it's the rain that makes their crests worse.
Oh, and if from the right stock, they're super friendly too.
Temperament is all about the strain though. I've heard loads of stories of aggressive or skittish Polish, most of which originate from hatchery stock the same that RIR stories do. Why? Because they don't breed for temperament. I've got a lot of hatchery gals, and most ended up very friendly, but no hatchery boys. However I've got some non-hatchery boys who are very friendly. Two of them only attacked me once when they were just 5 months old, and that was all.