Selection: I was off to Peru on a high level trek (abpve 4000m), which means when the suns shining its very warm but when its cloudy (and at night) it can be unpredictably cold. I was packing a RAB Infinity down jacket as my basecamp warmth but I needed a lightweight insulating layer I could use during the day if it got cold while walking. Primaloft is a leader in garment insulation so its the obvious choice and I settled on the Thermoshell because of its one of the lightest Primaloft Smocks available.
Performance: The Thermoshell did everything I required of it and was really enjoyable to wear. Underneath I had a winter weight long sleeved baselayer and I used the Thermoshell in the mornings rather than my down jacket, it was warm enough at -2C which was the coldest morning I recorded. When walking there were indeed times when I needed this extra layer on and it seemed to provide just the right amount of insulation, even though I was active.
I don't often choose Smocks because getting them on and off can be a chore, but the Thermoshell is spacious enough that I didn't feel restricted in any way. The front zip isa two way zip so you can open it from the top down to your chest strap, and from the bottom up. The hem and cuffs are simply finished with a loosely elasticated binding that is not restrictive in any way. I also liked the thumb loops which allow you to last longer before you have to put a pair of gloves on.
Styling is good, with reflective logo detailing. The Thermoshell comes with its own stuffsack which I left at home - not that its heavy - but every little helps. I didn't use or even think about the reversible functionality of the garment.
Other Comments: Other options I had for this type of garment were Montane's Fireball Smock and OMM's Rotor Smock. On paper the Rotor Smock seems higher spec'd than either the Thermoshell or the Fireball but I chose the Thermoshell because of its other features and styling. If you want a jacket that performs the same function but doesn't weigh much more - look at Montane's Fireball jacket - another garment we really like.