Don,t get over hung up on kit advised by sponsored runners. Start by deciding what you need and what can work for you. The lightest kit is not the best for this race. Fighting an ultralight zip in a snowstorm with frozen hands can put you out of the race.
Assume nothing will stay waterproof so Merino wool type undergarments which stay warm when wet are a must as I learned this year.
Kit lists from racers who have only done the race once will only only give you help from the conditions of that year. There are also several written by racers who never made the finish line. What works for the first few days may not be any good for the whole race.
This is what I put together after 3 Spines modifying the blog each time I learned more. (inc this years DNF)
At one point I thought I was getting the hang of Orienteering . Then at a night event one old guy walked past me at the start gate without dibbing. H took the map ,studied it for 5 mins then put it back in the tray, dibbed and walked off into the dark with no map. You guessed it he still beat me by 20 mins by memorising the whole course and run/walking it in the dark! I nearly gave up for good.
Strange things happened to feet this year. First point was no ones waterproof socks stayed waterproof. I got one small blister on the sole of my right foot. this was attended to by the medics at CP2 , By the end of the race it had healed! I always wear two pairs of Socks ( 3 including the waterproof socks). Most blister damage happens on day one as you move much faster and any rubbing is more severe . Once you slow down blisters are caused by bad fitting shoes or the early damage getting worse.
The medics always say I have good feet but I suspect it may be the double sock rule and the fact that ZT Wings are exactly matched to my foot shape (I can run an ultra in them straight out of the box.I don,t really have to think much about my feet.
With regards to conditions yes they were far worse than previous races hence the early high drop out race. The biggest difference this year was that the remaining pack did not have to deal with real sleep deprivation as we kept being held at CP,s.
No one was really tested by the lack of sleep so the later drop out rate was reduced to almost zero. If the race had carried on without the extra free rest time then I suspect we would have had only a 25% finish rate. I don,t think this years novice runners really appreciate how lucky they were. If they return in 2016 they will be in for an unexpected shock!
Lack of sleep will be hardly mentioned in this years blogs . GKD will tell you about sleep issues.
Garry used Spikecross for the first leg in 2013 but I think he abandoned them later due to lack of cushioning. Many Use Speedcross but they are not good on wet rock and again don,t have much cushioning. My way of looking at things is you need to have a shoe that probably is really good on rock. If you fall in mud you get muddy but if you fall on rock you can break yourself. Salomon XT Wings works well for me and have good toe box protection.. Any of the Inovate Rocklite soled shoes worked well. Hokas have lousy grip on most wet surfaces unless you replace the Sole with another type from a different maker.
As a general rule avoid any shoe which claims to be an ultralight version of an earlier model. I have seen shoes fall apart after just one hard day of Spine conditions.