And it was superb, not quite as stunning as the original overall but it's certainly far off. The story was just as moving as New Order and took somewhat of an unexpected turn during the second chapter (I won't spoil anything, but if you've been wondering when you'd see something supernatural...); the gameplay is still immensely satisfying and the pipes provide wonderfully visceral stealth kills whilst serving their purpose in map exploration and traversal and all the new weapons are on par with those found in The New Order.
It's just a great experience, and perhaps superior to The New Order in how it strays more towards Raiders of the lost ark (MG mentioned going for a deliberate 'B movie' approach to the expansion specifically beforehand, notably) than any traditional videogame portrayal of Nazis and Co. It's worth the £15, and it's as simple as that.
If Machine games can continue in this type of form then the next Wolfenstein will be special. And maybe, hopefully one day Bethesda will task them with the creation of the next Fallout; who better to resurrect an alternate history based game based upon the sci-fi of the era with the right mix of supernatural, gore and (plenty of) exploration?