As promised here is a product review for both. I have not had the luxury of getting my hands on the SKEDCO set. Quite possibly, it is due to the price difference. MSRP for the WALK is $1,500.49, while the SKEDCO (the cheapest one) comes in at $2,106.82. So cost effectiveness dictates that the WALK be in the Army system.
Reviewing the contents and packing side by side, I'd say both are equal. They come packed with trauma supplies (click on specifications), for multiple casualty management. Although, both are basic equipment with recommendations for additional supplies. They both also have configurations that carry a litter, with the the WALK coming in at 29 lb 15 oz, and the SKEDCO a beefy 38 and 50 for it's two respective variants.
For casevac purposes, the SKEDCO has more variation for sure, while the WALK is specifically designed around the Talon II litter. The SKEDCO carries both a Ranger SKED and a "quad-fold litter". Also, the SKED brings with it a great deal more flexibility by including the carabiners and various straps. While I'm sure this is what contributes to the significant weight difference, if it isn't being carried on the ground, then the flexibility is a plus.
The SKED also comes with more Medic goodies, like the Knife, Extreme Medicine®/Rescue , which I own and will review later, as well as an LED Headlight, etc.
It wouldn't be fair for me to pass judgement on the SKEDCO, since I haven't actually used it. As noted above, it's bigger and beefier, with more flexibility in evac configurations, although the size may hamper its deployability. OTOH, the Talon II is notorious for being stiff and a pain in the ass right out of the bag, and unfortunately, if we're honest, we don't take them out and exercise them enough. One thing I like about the SKEDCO, just from it's packing list, is it has a more signal marking equipment included, while the WALK only comes with an aviation panel. The SKEDCO looks like a nice piece of equipment and I'm sure it would do the job.
The Army chose the WALK as the one to put in it's supply system; and it does it's job. I only had to include some extra equipment to feel happy about it. I took out the hypothermia blankets and replaced it with a marking kit (smoke, signal flare, and the aviation panel). I placed an IV set with both ringers and Hextend in an outside pocket. On the front pockets, I added a few Hyfins and some Combat Gauze. The big thing is that I took a red permanent marker and marked what was each pocket. I treat each WALK as a comprehensive kit for one patient, and as a secondary go to bag. If the WALK comes out of the vehicle, then we've made a deliberate decision for Air Medevac and the configuration is based on managing that one casualty.
Overall, I like the WALK. It's simple with more than enough room to carry what you need. By no means is this a dismount bag and should not be carried on a foot patrol. But, don't make the mistake of packing it to the gills either. It completes the task it was designed to do and needs very little modification. The Army made a good choice on this one.