I'm really happy with this hoodie, get one while you can - Rab Endurance X Hoodie - Men's

This Rab Endurance X is a fantastic alternative to the Rab Xenon X with a much better price. They're very similar: they both have Primaloft insulation and a Pertex shell*, the ability to pack into a chest pocket with a clip for attaching it, a waist hem for cinching, a stretchy hood, and insulated hand pockets. Differences: the chest pocket on the Endurance X is on the outside rather than the inside, the torso is a tad shorter, and the main zipper is not a two-way zipper.

I'm 5'11", 168lbs and found that a medium fits really well as a trim/athletic cut. If I raise my arms way above my head, the jacket falls just below my pant waistband. Another inch in the torso would be nice, but it's fine. When walking around normally it fits like I'd expect, it's not too short at all. The sleeves don't feel bulky or too long. Sometimes people say the armpits of Rab jackets are too high up, but I didn't feel this and wouldn't even be commenting on it were it not mentioned elsewhere. I'm a medium in most jackets, but looking at other reviews made me opt for the a large initially. That would have worked but it was a little big, so I exchanged it for the medium.

As expected, this is a warm jacket, and breathabiliy isn't it's hallmark. Read the reviews of the Xenon X on Outdoor Gear Lab and elsewhere, same thing applies. This Endurance X is replacing a North Face Thermoball, which was never quite warm enough given that it also didn't breathe well. It'll complement a Patagonia Nano Air, which I'll use when I care more about breathability than warmth.

It's worth noting that the description of the Endurance X on Campsaver has a lot of odd information. This isn't a down jacket, and I'm definitely using it for more than running.

* There were no hang tags that confirm that it's Primaloft Gold inside or Pertex Quantum on the outside: I'm trusting the answers posted on Campsaver. There is a tiny "Primaloft" tag sewn into the jacket. Also worth noting, there's an answer somewhere that the zipper is two-way, but my jacket's zipper is definitely one-way.

Did I mention how great this jacket is? What a deal.