I am going to bikepack the Colorado Trail (500mi) during a 10 day ride this summer. I am looking for the lightest, smallest packing, best quality underquilt for these conditions to pair with my WBBB/MacCat Std. I really expect the lows to be around 40 but anything at altitude can happen. My first leaning was the Summer Phoenix--looks well made, pretty darn light. But the Warbonnet 3-S Yeti isn't much heavier and looks quite a bit warmer. From reading the posts on this awesome forum, it sounds like I could vent it just fine and it may be more versatile. But if it is overkill, then the Summer Phoenix may be the ticket. Money is less important--I don't get to do trips like this that often so I splurge when I do. Pretty please, love some advice.