I recently purchased the Rab Infinity Endurance Jacket and the Neutrino Endurance. They are both beautiful and well made. Being a Yank, I had to adjust to the left zipper. The Neutrino Endurance is slightly more technical. It has a two way zipper, which is mostly handy in a belay type situation for accessing your harness. The Infinity only zips up with one zipper. Both hoods are warm, but the Neutrino again is more technical in that the drawstrings are more friendly to a one handed mitten pull to tighten. However I actually prefer the drawstring pull back on the hood of the Infinity to the velcro pull back of the Neutrino. The Neutrino has hand warming pockets as well as an internal pocket with zipper. The Infinity has two hand warming pockets, an internal chest zip pocket as well as an external zip chest pocket. The cuffs on the Neutrino are able to be cranked tight over your gloves/mittens with velcro. The Infinity simply has elastic cuffs. The Neutrino is slightly heavier and warmer. For this reason it also packs slightly "bigger." If you want to look sportier in a comfortable but very warm jacket, get the Infinity. It looks awesome and is light wearing air, except you're toasty. If you desire the technical functionality demanded by glove worthy conditions, then get the Neutrino. I also have to throw in that both of these are stitch through construction. I cannot resist ordering the Neutrino Plus with narrow box construction. This should improve the warmth by making cold infiltration more difficult.
This review was written in the old system and had content requirements that are different than reviews written today.