Rab - Ultrasphere 4.5 Sleeping Mat

I just used the Rab Ultrasphere 4.5 for 15 nights on the Larapinta trail in Australia, which is basically entirely made of sharp rocks and very sharp spinifex plants with no flat ground. I admittedly used an Alton foam mat underneath to add some protection, which doubled as a very necessary sit pad whenever I wasn’t sleeping (and sometimes I still got spinifexed when trying to eat brekkie 😆). The only nights I had to put an extra puff or two into the Rab were the ones where there was a big temperature change from evening when I inflated it, to midnight (like, from 26C at 5pm to -2C at 1am) which I think i can squarely blame on physics rather than the Rab. I was really worried about the durability but had no issues whatsoever in the end, and there was only 1 night i felt a little cold (-2C) but I put my puffy on and slept like a baby after that. I loved the pad.

I bought long & wide model in July and used it few weeks ago in the beginning of September for two nights during a \~80km hike. Temps dropped below zero celcius during both nights (\~-2C or so) and that was no problem for the pad. It does feel a bit fragile so I would not want to deflate it on a rocky ground when packing it up. It is also a bit slippery as noted. Slightly angled tent pitch will cause it to drift to the "bottom" of the tent during the night at a slow pace. Sleeping wise it is comfortable for me (192cm, \~90kg) and the wide model is indeed wide enough for wide shoulder width. I can easily roll to the side during the night while hands and legs stay on the mat surface. Cannot complain about the price and the **weight** (the reason I bought it).

The only issue I have with mine is just how much it slips around the bottom of the tent when I move. I'd bring my foam mat to put underneath but I'm being an ultra lightweight twot at the moment and it would mean taking the rum out of my bag.

Rab Ultrasphere is like half the packed volume of a Nemo Tensor

The Rab Ultrasphere is a great UL all-arounder pad. First batch has had some durability issues (pinholes) but the problem might have been fixed since

Not sure what you mean. 20D is OK, Uberlite and Tensor Elite are 15D and 10D respectively. I don't see why the Ultrasphere would be "next in line" either

I feel like this is the case, there are like two people here with significant amount of experience on a Ultrasphere (which is way sturdier than the Uberlite or Nemo Elite) and everyone keeps repeating those anecdotes. FWIW I have 15 nights on my Ultrasphere without problems, but always slept in a tent