hi, i am one of the AMU players from oregon and i have won 2 of the last 3 cities with an AMU/mewtwo/palkia variant (also had a 3rd place finish in another tourney). this cities season in swiss play i am 25-7, never going worse than 4-2. i thought i would post to clear a few things up and to offer my opinion on others about this deck.
yes there is very little machamp in the oregon meta-game. it made top 8 at one recent cities and got bounced in the first round. machamp seems to have a very hard time against non-AMU/regigigas decks at the highest level. dusknoir is everywhere in the oregon metagame. i routinely beat dusknoir variants with AMU even with keeping my bench at three (for my first cities win i beat two dusknoir decks as well as a tyrantiar deck with a dark palm tech, all three players managed to get the dark palm guy established, i simply adjusted). IMO people are simply mistaken thinking that dusknoir has an advantage over AMU. despite the recent success of AMU the only person playing mewtwo in their deck is, well, me. all the dusknoir or gengar players seem more interested in teching in cresselia, starmie or bronzong than using mewtwo. besides let them try to play mewtwo, see if i let it live long enough to level up. gengar is a very tough matchup but not undoable (i beat a gengar/dusknoir variant in the round of 8 yesterday 2-0). a lot of it depends on luck and how the gengar player flips on fainting spell. also, tm-2 de-evolutor makes rare candied gengars very unhappy.
AMU is as tough a deck to play as i have ever run. you always have to be thinking two turns ahead. opponents tell me it is incredibly difficult to face because never know what it is going to do. this might be the turn where it supreme blasts for the third consecutive turn for 200 if i hit my energy pickup flip, or maybe it uses healing bell to patch up the entire bench, or maybe it will simply put a sacrificial pokemon active while charging up on the bench. because of all of the basics it is very hard to T2 donk with kingdra or such (i think i am like 7-0 against kingdra). in playtesting against machamp it all depended on setup. if i could avoid the t2 machamp and get unown g attached then i felt i had a reasonable chance. you would think luxray would have an insurmountable advantage over AMU but it doesn't and, like dusknoir, i have faced enough of them that my opponents have trained me in how to beat them now. spread attackers in general don't give AMU a hard time (though my one loss yesterday was to a abomasnow/weavile/bronzong rogue) because healing bell is stronger than any of their spread attacks. with nothing to KO through a cheap de-volution it takes a long time to grind down those high HP basics.
lastly let me just say that AMU is a deck that benefits from a large field of players because it is easy to overlook. two AMU players in a field of 44 is hard to tech against since there is a real good chance you will never face one of us (as opposed to the ten dusknoir players or the 3-5 kingdra players). also, AMU definitely benefits from a top 8 cut. for whatever reason i cannot get it to go undefeated, but it will routinely go 4-1. 4-1 is great but not always good enough to make top 4. OTOH i can pretty much always make top 8 and against the other archetypes which have survived the gauntlet, i don't believe any of them have an advantage over me.
i don't know what else to say. if anyone has any questions i will happily answer them.