We drafted the cube with 4 players, using 5 boosters of 15 cards each and burning the last 7 cards of each pack. Therefore there was no need to read signals much and everyone just got to build a nice deck!

Decks are in order of performance, best first. Funnily enough all decks included blue and all other colors were represented.

Deck #1:
Dimir low-curving self-discard with some good 4-5 drops.
Above and beyond: Any looter + Master of Death.
Strong standouts: No cards in particular, good gameplan, good deck. It played very smoothly with four ways to loot repeatedly and Archdemon of Ifnir, The Raven Man, Oskar, Rubbish Reclaimer and some others. It had enough value, some great removal (~6), some beefy beaters in Souls of the Lost and Cruel Somnophage and a very lean curve.

Deck #2:
Izzet aggressive spell slinger, self-discard deck.
Above and beyond: Prismari Command was almost unbeatable for artifact decks.
Strong standouts: All madness cards, Squee, Goblin Nabob, Third Path Iconoclast. The deck was aggressive and able to grind with madness cards and card draw. Prismari Command shut the door on several games against artifact heavy decks, similar to Kolaghan's Command. Overall a lot of red removal, making it very hard for synergy decks to get their engine online. Even more removal in the sideboard.

Deck #3:
Temur artifact synergy pile.
Above and beyond: Urza's Saga the one time it got played.
Strong standouts: Earthcraft popped off in one game. The welders didn't get there, too much removal. Overall the deck was a bit of a pile, without removal. Not quite a trainwreck but not cohesive enough. The idea was to see if Simic artifacts is viable and it might be lacking a bit lacking on its own. The artifact tokens worked nicely with welders though.

Deck #4:
Azorius aggro/midrange, mostly white.
Above and beyond: Palantír of Orthanc is basically a colorless Phyrexian Arena that scrys 2.
Strong standouts: Serra Paragon and flyers in general. The deck would have been stronger as mono white with some more removal out of the sideboard. In general it was a good deck in the hands of a less experienced player.

I get the feeling that some of the colorless cards are more powerful than their colored counterparts, e.g. Palantír of Orthanc. Maybe it would be better to cut some of these cards, either the generically good ones or the role players Crucible of Worlds and leave them in their colors Conduit of Worlds. The colorless space could be reserved for synergy pieces (Witch's Oven, Hollow One), glue cards Chromatic Star or to support aggro across more colors (Porcelain Legionnaire, Night Scythe). I still like the idea of artifact decks and that all colors can participate in it (black probably lacks support atm) but the artifact options should not generally be stronger than colored ones.

Another idea I am contemplating is to increase the black proportion of cards in the cube. In previous drafts decks with black in them were much more represented than other colors and if this frequently is the case then the people should get what they crave. Not in the next update but maybe in the future. It would also allow me to cut some weaker non-black signposts and add some sweet golgari cards back in.