Hello. My current sleep system consists of a WM Versalite (10 degrees, 32 oz) and an Exped Dowmat UL7 (R = 5.9, 21 oz). I'm planning to take my girlfriend backpacking more regularly, which gives me an excuse to purchase another sleep system.
I'm a slightly cold sleeper but have been very toasty with my Versalite and Dowmat UL7 in the low 30s. Living in Northern California, I have many coastal options that keep me out of snow camping in the foreseeable future, which means my setup is probably overkill much of the time. If I purchase some equipment for my girlfriend, I'd like to piece together a system that compliments what I have and reduces weight. Most of our trips would be in warmer weather where she will be very comfortable with the Versalite and Dowmat UL7, probably temps no colder than the high 40s (she is a very cold sleeper).
I'm considering purchasing a WM Summerlite (32 degree, 19 oz) and an Exped SynMat (R = 3.1, 16 oz). I like the idea of having the option to zip our bags together on pads that are similarly sized when we are together. This system would weigh 18 oz than my current one when I'm solo.
I've done some searching on BPL and have read some interesting topics on R value, but I'm still not clear on how the R value compliments the temp rating on bags. Specifically, how is the performance of the Versalite different with the Dowmat vs. the Synmat? I'd like to make sure that the combo of a 32 degree bag and 3.1 R-value mat keep me warm with just a baselayer in the 40s. And I'm curious how I could develop alternate pairings like the Summerlite with the Dowmat or the Versalite with the Synmat to optimize weight for the temp.
I'd love your feedback on whether this system of bags and mats provides good flexibility and performance for the weight, or whether I should really think about quilts.