So hardly an apples to apples comparison so irrelevant to which construction is lighter (Altaplex with inner in 0.75oz DCF and 1oz DCF floor including stuff sack = 487g; JH MH in 8oz DCF = 590g). Incidentally, Zpacks quote 465g for the, currently unavailable, camo Altaplex.No, but a real tree camo DCF Altaplex weighs 502g. My custom J.H. M.H. in real tree camo DCF weighs 445g, including the Exitex 1.5m x 3m Polycro ground sheet, and the DCF storage bag adds 10g. And if I want the very basics of flying insect protection I can throw on my Sea To Summit Nano head net, which would bring it up to 466g...36g lighter than the Altaplex.
I used to build Mclaren sports cars on the assembly line at their plant in Woking, and I saw first hand the benefits of bonded construction...Much of Mclarens cars achieve the amazingly high strength to weight ratio of their body shell and chassis, by effectively gluing the majority of their cars together, rather than bolting or riveting them together.
The Aluminium front and rear chassis rails, and all the fixed body panels, are all bonded directly onto into the immensely strong Carbon Fibre centre tub.
The reasoning is, a bolt or rivet always has a gap between it and the next one, and the next one and so on...But one part is not actually physically attached to another part in these gaps, leaving a weaker joint or fixing.
It is analogous to the hull plates on the Titanic being riveted, rather than welded...The Titanic would almost certainly have survived the collision with the iceberg and reached port safely, if it's hull plates had been welded, as it's hull would have been much stronger.
With a bonded (or welded) joint there are no gaps at all between parts so maximum joint strength between parts is achieved.
And it is the same with bonded tents.
And Colin Ibbotson is an aeronautical engineer, so presumably knows a thing or two about designing for strength.
I don't think you can compare the behaviour of bonded materials such as steel or aluminium with a heterogenous composite such as DCF. Colin's claim is that since the mylar (or other PET depending on DCF type) layers can delaminate from the dyneema fibres, sewing then bonding/taping is stronger than just bonding. My suspicion is that bonding is strong enough, though sewing plus bonding will be stronger*. Those of us with a fair amount of experience with DCF will know that the delamination issue is real. And if you ever try to remove tape from DCF (or to unpeel your seams, though why would you?), you'll find that you're more likely to end up stripping the layer of PET from the dyneema.
*Note that we're talking about sewing and taping here, so you do end up with "no gaps at all between parts".