The Arc'teryx Beta LT is a high performance lightweight hardshell similar to the Arc'teryx Alpha FL. In Arc'teryx's words, the Beta series is designed for all-around mountain use, and the LT means lightweight, with a streamlined set of features designed to save weight. It is made of 40D Gore-Tex Pro with no extra pit zips for ventilation, has a great storm hood, and excellent and easy to manipulate zippers. The major differences between the Arc'teryx Beta LT and the Alpha FL is that the waistline and sleeves are slightly shorter on the LT, and it features double handwarmer pockets and one internal storage pocket, as compared to the Alpha FL's single chest pocket. The LT also costs more, and seeing as they are very similar jackets, unless you really, really need handwarmer pockets, we are not sure why one would pick this jacket over the Alpha FL.
Weather Protection
The Arc'teryx Beta LT offers the same great weather protection as other Arc'teryx jackets we've used. The Gore-Tex Pro membrane is the most waterproof technology that we tried, and the storm hood offers great head and face protection with or without a helmet. The waistline is slightly shorter than the Alpha FL, and we have to admit that at least one time while out backcountry skiing we had trouble with it riding up too high while wearing a pack.
Weight
The Arc'teryx Beta LT weighs in at 12.7 ounces for a size large. This is remarkably light for the high quality Gore-Tex Pro membrane, but is still heavier than other lightweight jackets. It does not come with a stuff sack like the Alpha FL.
Mobility & Fit
Like the Alpha FL, the Arc'teryx Beta LT is cut to a trim fit, meaning there is room for a few layers underneath, but not something bulky like a puffy coat. Arc'teryx's superior design makes for a very mobile jacket, but it is not as comfortable or mobile as the Patagonia M10 or the Westcomb Shift LT.
Breathability
The new Gore-Tex Pro membrane is more breathable than older versions of the same stuff, although in our opinion not as breathable as the air permeable waterproof/breathable membranes like Polartec NeoShell. In order to save weight, it skips out on the pit zips and thus relies solely on the front zipper for venting.
Durability
Unlike the Alpha FL, we did not have the opportunity to test this jacket for years on expeditions to the far reaches of the world. However, with the same face fabric and membrane, and virtually the same construction, we are confident that the Beta LT is as durable as lightweight hardshell jackets come.
Features
Like the Arc'teryx Beta AR Jacket, we love the feature set on the Arc'teryx Beta LT. The main difference between the Beta and Alpha series is that this jacket features double handwarmer pockets instead of chest pockets. The Beta LT's pockets are large and sit high enough to rest above the waist belt on a pack or harness. However, this jacket does not have the Harness Hemlock feature like the Alpha FL, and the waistline is slightly higher, meaning it is not as suitable for climbing pursuits as the Alpha FL.
Versatility
Overall, this jacket is less versatile than the other Arc'teryx jackets, but still offers solid performance in the mountains. That said, it has more around-town applications than its even more technical competitors.
Best Applications
This jacket is designed as a lightweight all-around jacket. We guess that means that it would be best for backpacking, alpine climbing, and backcountry skiing. However, due to its particular feature set, we cannot envision a use where this jacket would be more desirable than the Alpha FL.
Value
For a significant amount more than the Arc'teryx Alpha FL and with significantly less versatility, we recommend that you opt for our Editors' Choice winner instead.
Conclusion
We highly doubt you could be disappointed by buying the Arc'teryx Beta LT, and indeed we think this is a well-constructed jacket made of top-notch materials. But, when the Alpha FL - a better jacket with more suitable alpine features - exists for less, we can't envision why anyone would choose the Beta LT instead.