Specialized's Windjacket is the lightest mac here by a long way, but it still offers useful protection. The styling is simple but the stretch fabric leaves plenty of room to move and there's enough stretch in the elasticated wrists so you can drag them up to your elbows for cooling.
Getting too warm in this jacket isn't much of a problem (not at this time of year anyway) because, although it certainly lessens windchill, it doesn't stop it completely and it can get shivery on long descents. Even after a few washes, light rain/drizzle/ fog rolls off without penetrating but it's still porous enough not to get excessively clammy on the climbs.
The lack of pockets or other features makes for a tiny 'can of coke' pack size and a forget-you've-got-it weight.
The pricing is also reasonable if you're just after a thin weatherproof skin over your thermal layers.