yes, it's true, i do know everything....thats why they call me miss informed!
the variety 'hidcote blue' has the #1 spot, imho. i've been growing it and using it for years. edibility? don't take the needles and eat them off the plant; you won't die, its just really bitter and then you taste lavender all day. i've done it.
hidecote blue used in an oil infusion adds a nice touch to things like rose ice cream. i also used it in a tomato tart and it was good! it's really more an aroma note than a flavor one....but hidcote blue has the least residual bitterness to it. white flowered lavenders are useless (someone's going to contradict this!) variety 'lavender lady' is useless in an infusion; weak. spanish type lavenders are deeply bitter and kind of cinnamony-lemony.
i use the needles fresh. dried needles have a musty smell, to me.