Long-sleeve mountain bike jerseys do appear to be harder to get right in terms of fit than their short-sleeve equivalent. Despite Alpinestars' Drop being up there with the best long-sleeve tops, it would still benefit from longer sleeves – on taller riders, the cuffs sit part way up the forearm and feel too snug.
The shoulders are superb though, with lots of room for movement so that the rest of the jersey doesn’t shift when you do. The body length is also good, and combined with a material that has a high degree of stretch, this creates a garment that’s comfortable on extended or more technical rides. The medium-weight fabric feels reassuringly substantial without being heavy and it wicks well. There’s one zip pocket and a lens cloth.