My order from STP came last night. Everything fits! The Icebreaker half zip really fits well, but it feels a little itchy to me. Well, I will be wearing it with something underneath. The 2 Icebreaker superfine short sleeved T shirts also felt a little rougher than the soft merino I am used to in sweaters. But I am now washing them, as the label said they would soften up with washing. They fit so well, I look forward to wearing them in the summer!
I also got 2 fleece v neck tops that fit perfectly. The sleeves on all of these items in x-small are a pretty good length, considering I usually wear petite sizes in regular clothes.
I am going to test out one or two of these pieces when I ride my Jamis today. Now I feel like a real commuter.