I've only had experience of catching haddock in norway, but i doubt they differ that much. We were catching then on pirks, hokkais and gummi makks. We didnt use bait at all so cant really compare.
What i will say though is their quite a hard fighting fish and seem to have really delicate mouths. The fight from them is very jaggy, if you know what i mean. We could tell almost straight away if we had haddock on. They are masters of escape and we dropped a lot. Play them gently but dont give too much away.
I'd reckon its location more than anything as there's very few of the poor buggers left.
there was a spot on the west coast we used to go, fished the bottom with lug, on a flowing trace or a boom. none left now, all gone to that great harry ramsdens in the sky I suppose (do they have harry ramsdens in France/Spain!)
Thanks for that Info Lads,must admit I have a liking to Harry Ramsdens as well,or at least here in Cork its Lennox's
Have found a delta Sonar Spoon very effective with Mussell as the primary bait and a sliver of Calamari Squid tipping it off on a size 2 Kamasan B940.
All suggestions most welcome as I find them to fight well above their weight in comparison to Whiting or Cod.