I like my slick bag but it did lose some warmth fairly quickly… now it seems like it’s staying the same, but it isn’t as warm as it was new (always stored hanging up, not compressed) down bags are just a better investment unless you are sleeping in wet mild conditions, they certainly hold loft better over time
I’m in the same boat as you, though I’m considering the 2 you are as well as feathered friends. I personally want a less roomy bag, because as long as I’m not freezing, I’m not a picky sleeper… probably because I have spent so many nights sleeping on the ocean on a 2’ wide bunk… and would rather optimize warmth over room, but I know I’m an outlier there. From what I’ve found researching, the SG is not very roomy in the bottom half of the bag, it seems to be the only complaint I can find on them, which doesn’t bother me.