Upgrading from my $5 REI stratus (scratch and dent find with a slow leak). What are my best options for high warmth low weight/small packed size? I found a Big Agnes Insulated Double Z on sale (R-value: 4.5 weight: 1lb 5oz packed size: 5"x8"). Use will be for 4 season camping in BWCA conditions (winter paired with a Therm-a-rest foam pad).

Exped Synmat 7 LW

I upgraded from a non insulated Kly Mat to a exped 7 LW mat last fall after my October solo up in Ontario. I have not tried it except on the living room floor as yet but it felt great there, I did get the schoozle thingy after I got it and it inflates much better, I will use the schoozle with a tee shirt pillow case for a pillow. FRED

Neo Air X-Therm. 15 oz for standard size mummy shape with a 5.7 R value, 2.5 inches thick. Comfy warm and easy to inflate with inflation bag. They also have larger sizes and even rectangular shaped. The large rectangular weighs 1# 7 oz. They are pricey when not on sale. Backcountry Edge has the regular rectangular for 139.00. They are usually 200.00 or more.

mgraber: "Neo Air X-Therm. 15 oz for standard size mummy shape with a 5.7 R value, 2.5 inches thick. Comfy warm and easy to inflate with inflation bag. They also have larger sizes and even rectangular shaped. The large rectangular weighs 1# 7 oz. They are pricey when not on sale. Backcountry Edge has the regular rectangular for 139.00. They are usually 200.00 or more."

Yep! If you're looking for something with the best combination of warmth, light weight, and small packing size this is the one. I'm very happy with mine. I got the max version which is the rectangular model. They're spendy though and some people online seem to complain about the crinkly noise they make, but everyone I've talked to in-person who has one doesn't seem to mind (myself included).

You won't really need to pair it with a foam pad for winter camping either (though it certainly wouldn't hurt). I've slept right on the snow with it.

I'm not familiar with the one you mentioned or your budget, but the specs sound pretty good. I haven't heard many bad things about Big Agnes pads (or products in general). I had an Exped Synmat 7 LW, which is a nice pad, but I replaced it with the Thermarest Neo-Air X-Therm LW, which is about half the weight, warmer and smaller. I found it on the Cabela's bargain shelf one day a few years ago and snatched it up. I've been very happy with it.

Another who uses an Exped SynMat 7. I'm not a winter camper, so I don't know how it performs then, but it's be excellent during the other three seasons.

I think what you list will work fine. The Double Z matches specifications well with the Snymat 7 and is good for 3 seasons. Adding a foam pad will get you the 4th season.
I used a BA Insulated Air Core and closed cell foam pad combination for a few years 4 season.
I feel the Exped Downmat 9 is probably the best 4 season pack-able mattress available. Pack size, carry weight, is close to the Double Z but has a 8+ R value (my go to mattress below 40 degrees), and has kept me warm for quite a few years.
As with many 4 season use items you will start to specialize some gear splitting 3 season and winter use. Something you might want to consider when purchasing gear. My Exped 9, is now used for winter, a 60 inch Downmat 5s gets 3 season use.

butthead

Klymit Insulated Static V or Klymit Insulated Double V

What you listed is a nice mattress pad. I think if it's within your budget then go for it. I like the idea of having a lighter weight pad for 3 season camping and a dedicated pad for winter. If you have more to spend then:

I think what Boonie talked about (Neo Air X-Therm or Max version) would be a better option since you are going to invest in a new pad. I take an Exped Down Mat 9 plus a reflective pad and an extra foam pad for winter camping. It seems you just can't have enough insulation under you when it comes to winter camping.

For shoulder seasons I take my Exped syn mat 7 because it is lighter, smaller and easier to inflate and deflate than my Down mat 9.

For deep winter camping, another vote for the Exped Down 9. For all other seasons, I use a Nemo Cosmo XL and I have never been cold on it. I also am a hot sleeper.

schweady: "Klymit Insulated Static V or Klymit Insulated Double V
"

+1

I've used Big Agnes Insulated Air core, Exped Down Mat 9, and a Nemo Cosmo Insulated 25" Exped is far and away the best insulated- none of the others are close. Use the Cosmo for most situations though- wider, packs a little smaller and way easier to inflate and deflate than the Exped. The extra width and length of the Cosmo makes staying on it a little easier. Exped is very comfy and warm.

unshavenman: " Exped Synmat 7 LW "

Compare the specs on the regular Synmat 7 and the Synmat 7 3-D. I find the boxed sides on the 3-D more comfortable.

I recently bought a long/wide QCore SLX and the 6 times I have used it so far it has been great. I am a big guy close to 400# and it has not given me any problems. I am a side sleeper and my body does not bottom out. I am going to try a Synmat for my wife as her 3/4" thermarest is getting handed down to the younglings.

Frenchy19: "For deep winter camping, another vote for the Exped Down 9. For all other seasons, I use a Nemo Cosmo XL and I have never been cold on it. I also am a hot sleeper."

Ive been considering the XL. How big is it when its packed?