Ultra 3R

As far as $/warmth ratio, this one is the winner. $50+ cheaper than S2S, Therma, Nemo and really comfy. I love mine.

The 3R is a pretty incredibly value for an 18oz pad at around $150. The 5R is probably better for being in Maine outside of summer.

Exped Synmat Ultra 3R. The comfiest pad for side sleeping that I have ever found, and it doesn't make the awful crinkly noise like some other mats (e.g. thermarest) do. Its pretty robust too. If you want a higher R value, they go upwards in model number - e.g Ultra 5 or 7, but the Ultra 3 is perfect for 3 seasons.

This is what I use and love it.

This is the pad that finally let me sleep

I am a fan of Exped pads, but do not have any experience with the new 6+R pads. I have 3 vintages of Exped pads including the Ultra 3R in MW you are asking about. My pad weighs 441 g and I would not use it for 20-30F as it would not provide enough warmth. From personal experience I think its limit is about 30F, so above freezing weather would be fine. But thanks for asking this question. Maybe I will ask for the 6.5R pad as a gift for my birthday?

+1 for this pad. I find it to be extremely comfortable and it comes with the best inflation sack on the market…doubles as a waterproof pack liner.

From your post history you seem to be based in the Netherlands. What is your budget? Hikingsite has a second hand market with currenty a nice offer for a used exped 3R wide model. A comfortable and light mat, good for summer. And I'm going to put a new unused Ether Light XR mummy on marktplaats for 120 euro (instead of 165). Good 3 season option, comfortable, light, small pack size. Let me know if that's something for you, I'm not in a hurry to sell it.