The lightest jacket tested, the Beta SL is a simple but well-designed garment. However it’s made from Paclite, which is the least breathable of the various versions of Gore-Tex, but costs the same as the Mountain Equipment Supercell/Cascade waterproof jacket, which is made from Active Shell, the most breathable type of Gore-Tex. The Supercell only weighs a touch more too. Arc’teryx does offer an Active Shell jacket with a similar design, the Alpha FL, that weighs less at 322 grams but costs much more at £350. Less expensive at £270 and even lighter still at 280 grams is the Tecto SL, but this only has one small pocket.
The Beta SL has good mapsize pockets though the bottom of them is cut off by a hipbelt. You can still get a map in and out however. The hood allows good side vision and good protection as long as it’s not very windy. The peak is only slightly stiffened though and flattens down in strong winds. There are no underarm zips, which would be useful in a Paclite jacket.
