I have the Facom 3/8" Rotator (J.360). Not used a lot (it's quite bulky), but I find it's more than a gimmick; smooth, nicely finished and genuinely useful for a couple of jobs (awkward-to-access suspension adjustments on a track car) which I've done with sufficient frequency for them to become tiresome without it.
What may not be obvious until you've handled one is that in 'twisting-the-handle mode', turning the handle back doesn't just recover its position - it carries on turning the socket in the same direction as you twist back and forth.
Is it worth the money? Hard to say - as I got mine along with some other stuff from a tool-merchant friend in return I did a small job for him, so it wasn't an easily quantifiable 'purchase'. I have quite a lot of Facom stuff (mostly older French-made items) so I was already well-disposed to the brand.