Well, the merino Tippis are my winter T-shirts. They are a thinner knit which makes them easy to layer under jackets. I've found that the V-necks are a slightly heavier gauge, but definitely still light enough to layer easily. I also don't have any trouble layering either one over a light-weight shirt or turtleneck.
I get a really good fit in the J Crew sweaters because J Crew tends to cut a higher, narrower armhole than BR. While I wouldn't call myself small busted (34D), I have a broad back and shoulders so I size up to a large which gives the sweaters an easy-fitting, fluid drape which flatters my non-existent waist. The high, narrow armhole keeps the larger size from getting too droopy in the side bust area. My pants size is one size down from my top size, so hips are never an issue for me.
I machine wash all my merino sweaters after a couple of wears because I often wear them next to my skin. I put them in a laundry bag on delicate cycle and then shape them and dry them flat. The J Crew ones last for several seasons, just getting softer and nicer to wear.
