I once gathered up four Therma-rests with slow leaks that I just could not repair and sent them to T-Rest. They sent me four equivalent “new” (factory irregular) pads as free replacements. I currently use either and NeoAir Xlite or Xtherm and love them both.
Went to a wide mat almost 6 years ago, half by chance as somebody was selling S/H at a good price. The S2S Comfort Plus may be a bit heavier than your limit tho I find it makes a huge comfort difference on snow
I spent 8 nights on my Neoair xtherm in September. I toss and turn alot, usually start on my back, go to my side and end up on my stomach. I had no problems in any position, in fact I would inflate my pad then lay on it and let some air out so it wouldn't be to hard. Also, it's advertised at 15oz. Mine comes in at 14.9oz. I know .1 oz isn't much but in a world where you see most manufactures lie about the weight of their products, it's a breath of fresh air to see someone advertise conservatively.
I've historically been a side sleeper but have been sleeping on my back more and more as of late. As much time as I spend outdoors I still consider myself a sleeping diva.... So with that said, here are my suggestions based on comfort in the backcountry... not counting ounces.
If you are truck camping and weight/pack-ability is not a concern, I highly recommend the Exped Megamat 10 MW. Its got an r value of 9 or so and is easily the most comfortable pad I've ever slept on.
For backpacking, I use a Big Agnes Q-Core Deluxe (Wide/Tall). Having only spent a handful of nights on it this year, it's done an awesome job so far. It's a thick mofo at 4.25". I've also found it most comfortable to have it 80% inflated -- it provides the right amount of 'give' without hitting my hips on on the ground.