Noooooooooooo, don't say that! I just bought my first bottle of the HP15 yesterday!I like that it's a young Highland Park expression that is non chill filtered and has a higher than usual proof for HP at 46.8%.
I'd choose the Dark Origins over the HP15.
Now you've forced my hand and I'll have to search out the Dark Origins too.
Good news though, the place I bought the 15 at had 18 for $112! I've never been able to get it for under $145, so I'll be going back there next week and picking up that bottle.
For anyone that doesn't know about it, the Highland Park 18 is one of the best affordable bottles out there.