Joining Two air mattresess with an iron

[Just Bill]

The only pad that cannot fail is a foam pad.
Barring that... Exped is now on the third generation of pads with improvements each time.
The internet is a small place... you sell a few thousand of anything and there will be a few failures posted someplace you'll hear about.
Thermarest pads had very high failure rates and likely there is not a person who has been doing this 20 years or so who hasn't had a thermarest pad fail. At any given time in our scout troop there were two busted thermarests out of 60 or so. So much so that troops exchanged ideas on repair methods and maintenance. We carried two spare pads in our troop trailer at all times.

Lately though it's relatively rare to hear of failures and thousands of happy campers go out each year for 30+ nights without horror stories abounding. Several hundreds of long distance hikers a year go out with hardly a failure.
So a grain or two of salt is needed, as is a bit of perspective.

For me... the Exped line has continued to impress. They have brought some very competitive pads to the market, innovated with the insulation as well as inflation methods and valves.
They are right there with the NeoAir series IMO regarding sizes, weight, pack size and durability.

I am a big fan of the Hyperlight series. I now own 2 hyperlights, a winter version I just picked up, and the Duo. Picked up two pillows too.
Since getting into hammocks more, these are far superior pads for that application. And the baffle orientation and design is a better one for ground use as well vs the NeoAir or Xtherm.
I recall some growing pains, but those largely seem to have been resolved. Nobody likes to be the 1: 10,000 that fails, but 9,999 other happy folks is pretty good for a 1lb sack of air you drag to the woods and abuse.

For the OP... I don't think there is a better double pad available for backpacking than the Hyperlight Duo series. Now available in two sizes and a winter version. The first model was a bit tight in size (IMO) for two adults who don't cuddle... but it was ideal sized for me and a kiddo. Now that there is a long wide model of that pad I'd imagine they have it covered.

For Tipi... I respect your circle of trust and what works for your trips.

Overall-
Backpacking is finding a balance between the reasonable and the absurd.
A reasonable option is to test your gear in safe conditions over a period of time. In this case (as with most gear) if there has been an error in manufacturing then it is likely to occur fairly early on. A 30 night quarantine period of use at home or car camping is something I tend to impose on new gear. After that though a dose of reality is in order. If you are truly in conditions you feel you are unable to cope with a gear failure; then you pack some redundancies into your system; such as a the foam pad that general wisdom dictates you bring in winter conditions.

If your skill level is lacking, or the area you are visiting is too hostile... then your level of redundancy and backup should increase.
Above treeline in the mountains in the middle of winter where walking out is not an option... I would have a foam sit pad at worst, or a 3/4 length z-rest.

If you have the skill level and resources available to you do deal with failures then the danger level is relatively low.
Suffering some catastrophic gear failure for 99% of us means at worst we suffer a sleepless night and abort the trip early.
In reality... Build a fire, a debris bed, stuff your pack with duff or spare clothes. Walk at night, sleep during the day. Get enough insulation together to sit on it and stay warm while sitting upright wrapped in your down, clothes, and other gear you have brought. Drink warm fluids.

If your kit is so fragile and poorly designed that a single piece of gear failing becomes a survival situation then you are lacking balance in your system.
If you don't have a plan or idea of what you should or could do to solve a loss of any component then you haven't thought your system out very well or need to study up.

One advantage the Exped pad has over other air pads is that it uses synthetic insulation.

Because of the synthetic insulation used; a half filled pad with a delam baffle should still provide nearly the full R-value at quite less than deadly comfort levels. Course never having had one fail or even seeing one in person I can't attest to the comfort of a busted baffle. Even in the case of total failure (which a delamed baffle seam hardly qualifies as) then the pad can be folded up and used as a fairly decent sit pad. In that respect it is a safer winter choice than the Xtherm or even a down filled mat. As mentioned- you can sit up on a pad and fight hyporhermia easily enough in that manner.

A quick comment as well on the side by side issues: Exped tapers the pads, but they are a straight taper. So they bump up next to each other much better than the rounded neo-air or other pads.
But I full agree with the others- nothing beats a single two person mat. Somebody always ends up 'in the crack' even if you manage to keep them secured.

PS- Tipi, you and I both damn well know that a busted sleeping pad isn't much more than a grumpy journal entry and opportunity to tell a tale. Quit scaring the children young man.
Hell- you could probably layout all your food, crumple up your book rolls and build a pretty good layer of ground insulation out of that if needed.
Ain't like you're doing Washington in the winter or soloing Long's Peak solo with an UL load.

[wordstew]

Well.... so far the posts have made for some good reading. I think we can all agree on a few things here. 1. Most of us are fairly curious about equipment, especially new equipment and potential equipment hacks. 2. Most of us have a few strong opinions about a particular piece of equipment they might own. 3. We all enjoy getting out there.

After some reading I may just give the Exped Duo another look. However, I still reserve the right to go mad scientist on my gear and do some experimentation...

[Just Bill]

Chopping down a pad and sealing an end seems like quite a different project to me than seaming up to pads side by side.
It's your money and mad science skills- but that strikes me as a very intimidating project with a high likely hood of failure for little gain.
The reason folks got into chopping pads was because the size they wanted (Short/wide typically) is not commercially available. In this case you have a very viable commercial option.

I've kept an eye out and picked up my pads on the REI member coupon (or moosejaw's matching deal) sales.
I just picked up the winter hyperlight single... it appears that Moosejaw is still running 25% off most if not all exped pads.

https://www.moosejaw.com/moosejaw/sh...8_10000001_-1_

Since I see that the Large/Wide version is available one can strongly suspect these are the third gen versions.
For some time there was some overlap and quite a few 'sales' on the 2nd gen that got confusing.
I have both 2nd and 3rd and there are some clean improvements on the 3rd round in terms of the fabric used.

[Just Bill]

https://www.moosejaw.com/moosejaw/sh...8_10000001_-1_

Winter version on sale too.