Well, it's not so much the deck as it is the player.
I've been playing competitive Yu-Gi-Oh for around two years, and I've been playing Blackwings off and on since then, but I've also been playing the deck throughout almost this entire format, so I know it in and out. To put it simply, I know what I'm doing. I know my bad match ups, I know my good match ups, and I know how to side in and out to cover those.
It just takes a lot of practice and experience. Anyone can be good at this game, you just have to be dedicated and interested enough to commit the time and effort to getting there. Ask anyone who knows me personally, I used to be god awful at this game when I first got back into it. I was playing all kinds of trashy decks with vanilla 1900 beaters and garbage equip cards.
It wasn't until, ironically enough, I saved up the money and built a Blackwing deck (this was right after Gale had been limited; Black Whirlwind was still at 3 and my friends were all telling me the deck was dead with only 1 Gale -- boy were they ever wrong), that I really started to get better. Blackwings were the first deck I ever took to a tournament, and while I went 2-2 that day (still pretty respectable, IMO), I've only gone up from there.
Now I have two YCS's under my belt; Nashville last February where I went 2-3 and dropped, and Atlanta this past November, where I went 5-3 and only missed making day two and possibly top 32 by one game.
My point is: Practice. Practice. Practice.
Copying a deck isn't going to get you anywhere, you have to learn the basics and the real depth of the game to be good at it.