Anybody used Actis Tri Iso Super 9 insulation?

In article , Kim writes

I haven't used it, but I notice that the U value calculation was based on a structure that had a 25mm airgap on each side of the insulating material. This would give the material the best opportunity for its reflective properties to work but means that to get the best effect you require a 75mm cavity and a structure to support the material in the middle.

I haven't looked at the U value measurement method for celotex, but I bet it doesn't contain such a restriction.

Plus a quote from a Eurima journal (the mineral wool body, so don't expect any favours):

For anyone contemplating the use of a reflective foil insulation Eurima can do no better than to repeat the advice offered by Peter Warm, energy consultant, in his article 'Reflective, thin insulations- winners or loosers?' viz., o Be cynical about claims for tests results unless they have been carried out to BS 874 in a hot box method o Combined Reflective/ Convective insulation such as that marketed by ACTIS should have a lower conductivity than air based products fibre products, but not 6 times lower. I assume 1.5 times lower i.e. a k value of 0.027 W/mK but add in the requirement for a clear 20mm cavity on either side, which reduces the effective thickness that can be installed. o I account for all thermal bridging. Thermal bridging and radiation is critical in radiation insulation because it can completely destroy the insulation value locally around the thermal bridge