For anyone that is interested in a followup to my initial inquiry…
I ended up getting two of these Big Agnes Air Core SL pads in the Regular size (one for me and the other for my wife). They are officially specified at 20x72x3.75 inches and 17 ounces in weight.
I measured both pads for myself and found the actual (fully inflated) dimensions to be 19x71x3.75 inches and 18.3 ounces (19.1 ounces if you include the little stuff sack and repair kit that comes with the pad). Both pads came out exactly the same when I measured and weighed them.
While the actual dimensions of the pad are certainly less than the officially stated values, I'm finding that I don't mind too much in this case. The 19 inch width is actually useable over its entire range, even near the edge. It doesn't seem to collapse as much at the edges as the NeoAirs do, so in reality, this pad feels wider than a 20" wide NeoAir. It is also not crinkly at all, which is a nice bonus. And of course, it's truly rectangular, which is a big selling point over the new NeoAirs right now (at least in my opinion).
It's also very comfortable… Like, as comfortable, if not more, than the Big Agnes Q-Core pads. At least Big Agnes didn't fib about the thickness of this Air Core SL pad. It really is a full 3.75 inches when fully inflated. I have yet to bottom out on it while laying down, even while tossing and turning. Side sleepers should have no issues with this pad. It feels quite stable and supportive, with the I-beam construction seeming to do its job well. Also, the fabric on the pad feels substantial, inspiring much more confidence than, say, a NeoAir XLite. I don't think I'm going to feel the need to baby this pad.
It took me 3 minutes and 18 breaths to fill each pad (I wasn't trying to break any records, just a sustainable pace). There's certainly a lot of air to blow in there, but I haven't found it bothersome to inflate.
Also, I actually don't mind the 71 inch length because I'm 5'10", so 71" is just about perfect for me. Those 6 feet or over, on the other hand, may feel a little short changed with the Regular size. If you are over 5'11" I would suggest getting the long version for sure.
The higher than specified weight of this pad, on the other hand, is quite annoying. I wish manufacturers wouldn't do this. I mean, if it weighed 17.6 ounces or something I wouldn't make a fuss about it, but we're talking about 1.3 ounces overweight on a 17 ounce pad. That's a little too much to just brush over in my opinion.
Still, I think my wife and I are going to like these pads a lot. We took a nap on them today and were both very satisfied with the feel and comfort of the pads.
I suspect that they are going to fill a nice little niche as an extremely comfortable summer pad (assuming they will actually keep you warm down to 35 degrees fahrenheit, as stated by Big Agnes). These pads are substantially cheaper than NeoAirs, more comfortable in my opinion, and most likely more durable (and not noisy!).
This pad is certainly not ultralight at 18.3 ounces, but it sure is plush for that weight. Gram weenies will certainly stick to their NeoAir XLites for their plush sleeping needs, but for those that mainly backpack in warmer weather and want a super comfortable pad at a decent price without too much of a weight penalty, this pad will probably fit the bill.
If anyone has any questions about this pad, I'll be happy to answer them the best I can. I'll probably do a full review once I get to test it in the field for a substantial amount of time, since I still haven't found a full review of this pad from any end users yet.
