While I haven't had a chance to wear them for long my first impressions are that finally I've found a couple of midlayers that work together and are long enough in the sleeves to fit a beanpole like me.
While supposedly long enough to cover the palm of your hand in the cold weather position the sleeves are a tad short for that on me but on anybody else I suspect they would come down to the fingertips.
The centre zip is cut deep enough to come down to the waistline/hipbelt for venting when hot and just as the sales blurb says the body cut is such that extending your arms above the head does not pull the shirt above your belly button as so many pile shirts do these days.
The best part tho is the close fitting balaclava style hood, moves with me and never comes close to obscuring my vision.
Not cheap but if it means not loosing another balaclava that will pay for itself
Most of these comments also apply to the nanopuff bivvy
Personally I really prefer pullovers and while it won't be as warm as my old PuffBall it will come close as it uses GOLD insulation at 60gsm AND THE NEW INSULATION IS PROBABLY ALMOST EQUAL TO THE 100gsm IN THE PuffBall OF 30 years ago
EDIT
to add links
http://www.patagonia.com/us/product/men ... ?p=84185-0
http://www.patagonia.com/us/product/men ... ?p=40074-1