You have my apologies for not replying to this thread sooner but I've just spent a rather unexpected 2 weeks in hospital
The replacement mattress was sent first class and I received a message on my phone the same day telling me what time to expect the delivery, including the option to postpone the time or have it left with a neighbor if I wasn't about.
I received the same model, in a different colour and this is presumably a more updated version as it is lighter and seems to pack smaller than my old one. The outer material is completely different, the old one was a very abrasion resistant plastic and the new one is a much thinner sort of nylon/polyester material.
It doesn't seem to me as though it can be as hard wearing as the old one was but considering I am thinking about converting over to hammock camping in the near future then I would imagine that it will suit me just fine.
The company dealt with my return well within the allotted time frame and kept me in the loop every step of the way. I have the option of returning the replacement but I've decided to hang onto it and see how she does.