There's light, and then there is ultralight. And ultralight these days has gotten crazy-light, thanks to companies like Therm-a-Rest. Their Vesper quilts is about as minimalist as you can possibly get in features, and it doesn't give an inch on performance to get there.
The idea behind ultralight is simple: the lighter your gear, the easier the hiking. The easier the hiking, the more time you spend doing that instead of resting, setting up camp, tearing down camp, etc. To paraphrase the guru of ultralight Andrew Skurka, the weight and complexity of your gear determines whether you're a hiker or a camper. REI recommends a backpacking backpack weight about 20 percent of your bodyweight - that's 40lb for a 200lb person! Even for day hiking they recommend 10 percent, which is still 20lb for a day out, which we think should be your target weekender weight.
The Vesper quilts can help you hit that target. Available in 20F (32F comfort), 32F (41F comfort) and 45F (52F comfort) temperature ratings, and two sizes each (regular and long), the weights range from 12oz for the 45F regular to 21oz for the 20F long. We tested the 32F long, which tipped the scale at 19oz inside the included compression sack.
So what exactly are you getting into here? The Vesper is a quilt with a foot box. It starts with 900 fill responsibly-sourced Nikwax hydrophobic (water resistant) down. Hydrophobic down is important not just in case you get it wet from some external source, but because you eject about a pound of water overnight through breathing and sweat. If you've ever woken up to icicles in your tent - poor ventilation management! - that's why. All that exhaled moisture floating around can compromise the warmth of your quilt or sleeping bag, and that is what hydrophobic down helps prevent. The other major design consideration of the Vesper is the box baffle construction, which means no sewn-through cold spots.
The advantage of all this is less material and weight than a full quilt, and better warmth especially around your feet due to the decreased air space. Keep that down close for maximum warmth! The other major design feature of the Vesper is the SynergyLink Connectors, basically a tether with a T connector at either end that fits into loops on the side of the Vesper. This pulls the quilt snug around a sleeping pad like the Therm-a-Rest UberLite to minimize air gaps and shifting during sleep. In this case the sleeping pad is your insulation against the ground, which makes sense since almost all the insulation below you in a full sleeping bag is useless since you've fully compressed it with your bodyweight, leaving no ability to loft.
The Vesper has draft tubes along the sides and around the neck, as well as a snap closure at the neck for additional control. Therm-a-Rest includes both a compression sack that squeezes the quilt down to to just larger than a quart/liter bottle, and a larger storage sack. Overall we find the Vesper hard to beat for shaving major weight off the big three: tent, pack and sleeping bag. With the combination of UberLite pad and 32F Vesper weighing in at just over a pound-and-a-half, you should be able to keep the big three under 10lb. That's a damn good start.