In reply to HHay:
i can't speak for the transition, but have worn the Kinesis and the Proton LT and tried the transition on in store.
The Kinesis is defininetly the most windresistant, maybe even windproof. The outer is thin like parchment. It dries really fast even in humid conditions but it's also fragile i guess. Dave MacLeod wears it in most of his videos while climbing so its either tougher then expected or being sponsored gets him a new one everytime it got shredded.
The inner fuzzy liner is some hollow core yarn insulation, like the one used in the Proton FL or the Rab Paradox Light. But in this case its fuzzy like polartec alpha direct and not lined. The marketing claims that its an evolution of Polartec Alpha with better microclimate and thermal management and wicks faster. After some use i can agree. Looking at the new gear from the ISPO this hollow yarn might be the next step for action suits. I think it mimics the properties from polar bear fur? It has a really cozy feeling and wicks sweat really fast in combination with the outer. I wore it with a LS Tee hiking in 15°C and for running aerobically, layered with a ME solar eclipse hoody around 0°C. I had both times a super comfortable feeling, minimal sweat build up while feeling warm and no wind came through.
I do have a Salewa Pedroc Pertex-Quantum+Polartec Alpha 60g/m^2 jacket that gets clammy faster and isnt as warm as the Kinesis. So it made the salewa pretty much obsolete. Only thing that bugs me is that the fuzzy insulation grabs onto your layers beneath. The Hood is roomy enough for a helmet and it packs into a pocket twice the size of a packed Squall or a 2l bladder/1,5l Nalgene. Mine does also have a dual slider zipper which is nice. Not sure how good it insulates while being static but i might use it in summer for climbing/belaying.
Summary: Current go to Jacket for aerobic activities for changeable weather with no to minimal sunshine.
Regarding the new Proton LT i can't say much. Haven't used this one that much and mostly walking to the gym. But you probably read the nice review above anyway. But i can compare fit and wind resistance on the Transition in comparison to the LT. Both seem to be comparable in terms of warmth and warmer then the Kinesis. I wear a medium in both brands for jackets.
The Proton LT fits me better and is less restrictive around the shoulders. The Transition feels a bit slimmer in waist and shoulders. The medium already felt tight around the shoulders. The Proton has more room to layer and offers more freedom of movement, but is still tailored well. The Transition is also slimmer as the Kinesis.
The Proton is marginally less wind resistant and the Coreloft insulation doesn't need stitching which is also good against cold spots.
Summary: Try it in the shop. It comes down to how they fit. Both jackets are warm for activities in the negative degrees and breath well, but i feel personally that the design and fabrics on the Proton are better.