The Winter Alpine Leaders Pack

A common practice for alpine climbs, with difficult terrain, is that the leader climbs without a pack or with a very light pack and then the seconding climber climbs with a heavier pack or, in some cases, the big pack is hauled.
I have just obtained a new piece of the puzzle in the quest for the perfect gear to meet the needs of the 'leader pack'. The 'needs' are it must be lightweight, simple, pragmatic, and just tough enough.
The new Sea to Summit Ultra Sil Daypack http://www.seatosummit.com/products/display/86 is the ultimate pack for a 'leaders pack'....and you can get it for less than $30. This pack is also useful when I am guiding to give to my clients or for climbs where you end up coming back to the base and don't need to bring everything with you.
All of the below necessities will easily fit into the 20 liter pack for a light and tight package. The shoulder straps are bar tacked on and the siliconized Cordura is super tough for the weight. The fact that the material is very 'slippery' also help it from getting snagged on all but the sharpest rock or equipment. The one thing you may want to do is jury rig a sternum strap which I will do with 3mm cord and an accessory biner.

My typical package is as follows:
1. Patagonia Das Parka: with 170g of Primoloft One it offers good protection from the elements even when a bit wet. In demanding alpine terrain things will get wet and down insulation is a bad choice. On warmer days you could replace the Das Parka(http://www.trailspace.com/gear/patagonia/das-parka/), with the Micro Puff Hoody (http://www.trailspace.com/gear/patagonia/micro-puff-jacket/) or Nano Puff (http://www.patagonia.com/web/us/product/patagonia-mens-nano-puff-pullover?p=84020-0-804).
2. .5-1L of water or sport drink
3. A first aid kit aka a role of good quality tape and perhaps some hard pain killers. Really what are you able to do when hanging from a couple ice screws. You can stop bleeding(tape), splint(tape), and numb the pain(drugs).
4. Energy: in form of bars, gels, cheese, and dried meat.
5. Tikka2 XP Headlamp(http://www.petzl.com/en/outdoor/headlamps/compact-tikka-2/tikka-xp): I have more than once been caught by darkness mid-pitch on something that looks like I would cruise but.....
6. Extra Gloves/Belay gloves

A good tip is to keep all the small items (food, lamp, tape) in the pockets of the Das Parka so that when you pull the jacket out everything doesn't fall out of the pack.

This is what I use. Other thoughts?

The photo to the left shows the meat of the "leaders pack".
The photo below is the Sea to Summit pack stuffed into it's own sac.