The Neutron is a comfortable and lightweight waterproof that's a good outer layer for year-round riding. The 2.5 layer breathable fabric is very lightweight but shrugs off the rain well, and it's pretty breathable too – normally I'd keep my outer layer in my bag for the commute home (2 miles, all uphill) but the Neutron doesn't cook you on the climbs.
It's not especially warm on the way down either, despite being completely windproof, and it definitely works best as part of a layering system. There's very few breathable fabrics that work well in direct contact with the skin, and this isn't one of them, so wear a long-sleeve base layer to get the best performance.
Luckily there's lots of room for your layers, as the Neutron seems to adhere to the more traditional Polaris rules of sizing. Unlike the last two Polaris tops we've had, the Niteride II and the Vortex, the Neutron is a very generous XL. at 1.90m and 105kg I'd normally expect to need the largest size going (and even that's not always big enough) but the Neutron is plenty roomy on me with two thick layers underneath, and there's an XXL too... probably best to aim small if you're race build.
There's plenty of fabric in the arms too, which are good and long and just right on the bike; The cuff tabs keep the wind from blowing you up like a weather balloon. The dropped rear is elasticated and adjustable, as is the collar. Waterproof zips are used for the main closure and the chest pocket (the only one you get), and there's a good helping of reflective too.
All in all there's a lot to like; it's a versatile jacket that works well with other layers and packs down well, so it's a good choice for most riding. It's a bit too loose for the real fast stuff as it tends to flap a bit at speed, it's a bit on the expensive side for what you get, and it could probably do with another pocket. But overall it's a likeable and usable outer shell.
Available in: Flame Red, Kiwi Green