Decided to buy one myself, order just gone through, you tempted me too much Richard! Solid inner made the difference!
Seems Nordisk are advertising tear strength of 15.1kg for their 40D flysheet fabric, which is sil/sil (both sides) and comparable to Kerlon (Hilleberg's fabric) in that respect (also 40D triple applied sil/sil)
Kerlon 1800 is used in Black label mountaineering tents and has a TS of 18kg, Kerlon 1200 is used in Red label tents and has a TS of 12kg which would put the 'storm worthiness' somewhere between the two. It also uses 9mm alu poles, like the Hille Red range.
So essentially it's a mountaineering class tent with a convertible solid inner which probably doesn't handle snow especially well, for a quarter of the price of a Hilleberg Soulo. Most cheap and cheerful summer tents have 2-4kg TS, for comparison.
Considering the cheapest Black label Hille is about £1100 it's certainly worth a punt. I'll probably pick up a selection of pegs to match the season to go with it depending what arrives. Expecting the weak points to likely be the groundsheet (might want to bring a small tyvek sheet to protect it, even polycro is better than nothing).