I've messed with it in a couple of brews.
First thing, this is not a crystal malt, but a roast malt. It's not as dry and savoury as biscuit, but seems to my palate to fall somewhere between a biscuit and a Belgian aromatic, with an emphasis on caramel flavour.
10%-12% seems a sweet spot for getting the caramel flavours into an IPA without getting into the melanoidin territory. That was my interest in it. Adding caramel flavour without non-fermentable sugars. It has not yet proved itself to be a drag n' drop solution though. It definitely has promise, but IMHAO it is sensitive to the rest of the malt bill, as well as to intense hops. I'm wanting it to play a supporting role, but haven't yet found the ideal way to integrate it yet.
After messing with it a bit, I think the way I need to test it - which I haven't done yet, but intend to - is have a go at a 90% pils/10% Supernova with low hops.