Anyone used YBS SuperQuilt loft insulation

In article , Martin J. Evans writes

Have never used and would never use as it is highly unlikely that the claimed results would be achieved in a typical installation. Same applies for all the foil/metalised plastic sandwich and bubble wrap products.

The only insulation product I would use in a boarded out loft is PIR foam board such as celotex, kingspan or ballytherm. It has the greatest insulating factor per unit depth of any domestic product and is proven to work with just a little care in installation. Buying seconds with cosmetic defects can offer significant savings over pristine product.

in a similar situation to you and so was looking at this but it appaers quite expensive it appears that you need 2 layers + 20mm of some sort of pir foam board to get the eqivalent of 270mm depth of rockwool. at least according to

I have just bought a load of seconds on 60mm PIR boards (£3.25 for 4' x 2' boards) and will lay thopse on the boarded areas with hardboard on top

to bring the U value to the equivalent of the recomended 270mm rockwool you really need 100mm of rockwool and 80+mm pir board but cant afford that :-(