I only made it to day 2 but here's what I learned:
-Water: stops up to the RV park are reliable and every 25 miles or so. Anza Sunshine market, then a liquor store in Borrego springs, then a store in Ocotillo Wells, then Stagecoach RV. Beyond that, someone else will have to fill in. The cue sheets the Hub supplies are good.
-Capacity: depends on how fast you are. I ran out of water in fish creek. 3L proved not enough for that stretch. I carried a spare 4L dromlite which I neglected to fill at Ocotillo before going into the wash. Duh.
-Tires: I think more important than type of tire is what pressure to be running when. There is a huge amount of soft deep sand the first day and learning to ride through it or around it is super important. I was running 25psi in there which I later realized was way too high.
-Temps: it was downright pleasant in the desert last year at night. I heard a rumor they might move it up earlier this year though.
These are the links I had bookmarked prior to this year's race (route changed a bit since then though):
http://www.bikepacking.net/forum/index.php/topic,3146.0.htmlhttp://www.bikepacking.net/forum/index.php/topic,5429.0/topicseen.htmlhttp://www.bikepacking.net/forum/index.php/topic,3047.msg29380.html#msg29380http://www.hubcyclery.com/stagecoach-400-scouting-run/http://sirenmary.com/tag/stagecoach-400/http://rolandsturm.blogspot.com/2012/05/stagecoach-400-day-1-first-bikepacking.htmlhttp://calestravels.blogspot.com/search?q=stagecoachhttp://sergekeepmoving.blogspot.com/2012/05/stagecoach-400-almost-final-but-long.html