I just want to add my two cents. I don't know if anyone really gives a shit what I have to say on TD anymore, but I figured I should add my piece to the story. To clarify, I never played with Ace until recently or talked to him anywhere else besides in-game (until today, that is).
I specced him quite a bit over the last week and never saw anything that I thought was overly fishy. Whenever someone is playing "too good to be true," I spec them. I'll also watch people just to learn how to play maps better/aim better. I've done it with tytanium, ballonhands, walker, rex, grimesy etc., After playing CS:S, I'm still paranoid that everyone is walling :) I don't know how many people are still around from the Mahone days of TD, but anyone who was active then can probably attest to the number of players I demo'd and reported for walling in CS:S. If anyone remembers "3xtr3m3," I was one of the first to call him out before he got banned. I assume everyone is hacking until I feel confident enough to say they aren't.
What I look for when I spec people is the ability to always focus on the area other players are in, when people stop in their footsteps when they have no reason to (ie knowing someone is in a certain spot, so they uncharacteristically wait until the person pops out), their ability to aim through smoke/double doors, occasional slip-ups when they pre-fire, behavior in switching bombsites when it's 1v1/3v3, covering the flanks always at the right time, chasing someone who flanked that snuck by solidly, etc., I never consistently saw anything to make me move to step two and start demoing ace.
From my observations of Ace: he often missed players behind smoke, didn't check the odd corners and got wrecked, and often had people on his screen that he didn't instantly aim at. Regarding his playing style, I saw that he played very thorough and pretty much "knew" all the spots and checked them, even when people weren't there. He was very thorough, but too sloppy to be always walling. He turned back from danger, but also turned back from no danger (ie bombsite is open and clear, he turned around).
Regarding his aiming, I think it's on par with his playstyle. From my experience, wallers usually have bad aim, but somehow amazing "strategy/playstyle." They always check the right corners, rush at the right time, etc., But.. Ace had pretty damn good aim, some of the best aim I've seen. Unfortunately, I don't really know what CS:GO aimbots look like and I'm not the best shot in GO, so I can't really say that he wasn't aimbotting. But, I think his ability to shoot was on par with his other skills.. so I'm lead to believe that the guy might just be good.
I specced him probably ~2-3 hours over the last few weeks/in the past when I died. It's very possibly that I missed the signs and by no means can I say he's legit, but just based on what I saw I didn't see anything that made me think he was BS. I truly hope the evidence on his ban is good and that my observations are wrong, it's just a bad precedent to set when you start banning members of the community based on gut feeling. Truth be told, at one point I was convinced Copper was walling for a good 1-2 weeks.
Also from my observations: his KDR/score is good because he usually disconnected when he was on a losing team and only played roll-maps.
edit: (((((BTW A WILD KEL HAS APPEARED)))))