http://www.wizards.com/Magic/Magazine/Events.aspx?x=mtgevent/gporl04/dt1
Matt Boccio won a Neutral Ground PTQ last weekend with Frank Karsten's Vial Affinity deck, with his only loss on the day coming to mono-Red. He added three Somber Hoverguards to the main, taking out 2 Myr Enforcers and a Cranial Plating because he didn't find Myr Enforcer that exciting at the PTQ, while Hoverguard seems really good against the Green decks since they have no real way to deal with it. He also dropped a Myr Retriever for a second Atog for the Red matchup, saying "Almost every time you cast Atog, it is game over for the Red decks, and I was having more trouble with that matchup that when I was playing Green." He also added a Glimmervoid and took out a Blinkmoth Nexus to make it easier to cast the extra colored spells. In the sideboard he packs an extra Glimmervoid plus three Shatters and three Shrapnel Blasts.

"I think Mantle Affinity is a little too slow. Some of my friends played it at some of the earlier PTQs, and they were always a turn behind. The reason why Affinity can beat any deck is because it's just too fast, and the Mantle version seems to give your opponent that one extra turn to recover, so you lose more."