So What is Gore-Tex Pro Shell?

Gore-Tex XCR has been W.L. Gore's high performance waterproof breathable membrane for a few years now, and Pro Shell is a replacement for this.  "Classic Gore-Tex" is remaining unchanged but being re-branded as Performance Shell.  Like XCR, Pro shell is aimed more at climbers, mountaineers and more adventurous hill walkers; with Performance Shell for everything that doesn't fall into those categories.  Both will be available in two and three layer flavours. So what's new about Pro Shell?  Well it is essentially still the same Gore membrane but with a scrim (that's the fabric on the inside of the jacket) that is woven rather than knitted.  This is more important than it may at first sound, giving several significant advantages over XCR. 

Texture

The new scrim is smoother than the old XCR was.  This means the fabric has less friction when rubbing against other surfaces, and so it is more likely to slide over sharp objects rather than tear.  This reduction in friction will also mean there is less rubbing between the inside of the jacket, and whatever you are wearing underneath.  Arguably this will make Pro Shell a little more comfortable to wear if you only have a short sleeved base layer on, compared to XCR.  It will also reduce the wear on any of your layering garments, as it slides smoothly over them rather than speeding up the pilling of your fleece.  This smoother fabric should make getting garments on and off a lot easier, which can only be a good thing!

Weight

The new scrim makes Pro Shell lighter by about 15%.  In a medium to large size jacket, you are looking at a weight decrease of between 60g and 80g.  This is a fairly significant amount of weight loss and brings down the weight of a Pro Shell jacket to that of a Paclite jacket from a few years ago, whilst retaining the durability of a full-on mountain shell.

Durability

The next advantage of the new scrim is that it is more durable than the old knitted version.  Now the main wear on a jacket is from the outside of a garment, and it depends on the face fabric how well it will deal with this.  However, if the fabric is getting lighter then you can't complain about it getting stronger!  Hopefully your Pro Shell jacket will last a bit longer, at least from any nicks and scratches that you might pick up on the inside of the jacket.

Breatheability

It's what you have all been waiting for, how breathable is Pro Shell?  Well it depends who you ask.  The new scrim has made Pro Shell more breathable than XCR.  However, one of the limiting factors of any membrane is the face fabric (the fabric on the outside of the jacket that protects the delicate Gore-tex membrane).  All face fabrics impeed the breathability of a membrane, but without it the membrane would be shredded within minutes of use.  Different face fabrics will have differing properties: weight, tear resistance, strength, flexibility, as well as colour choice and price.  Breathability is one of these properties, so Pro Shell will breathe to a varying amount depending on the face fabric, just the same as it varies with any other membrane.  However lab tests have been done on many different face fabric/Pro Shell combinations, and some of these have been very breathable, even more so than Event.  However, in other types of breathability test, Event does better, and none of these tests truly represent what happens in the real world as there are far too many varying factors.
Another consideration is the skinny 11mm (or sometimes 8mm) tape that is being used on Pro Shell jackets, frees up a greater surface area of the jacket by about the size of an A4 piece of paper, again increasing breathability. Pro Shell will also be marginally cooler than XCR due to its increased breathability.


Conclusion

So is Pro Shell more breathable than Event?  It will depend on the jacket, but I would say that they are much more on a par with one another than XCR was.  However other things to think about when buying a Pro Shell jacket is that it will be a bit more flexible, lighter and more durable than XCR was.  However, the features and cut of a jacket are at least as important as the fabric, so I would recommend trying a new jacket on before buying it.