Are you still a winning player? Were you playing before Black Friday? I heard it was easier. I studied the game a lot these past few months and I barely break even. I'm only winning in live poker.
I would say that by 2008 the average live game was strong enough that I definitely had to practice disciplined game/seat selection, couldn't just sit down anywhere and expect my edge was higher than the rake.
I agree HU strategies advanced exponentially once stoxpoker and some other video sites came on and people started being heads-up specialists.
Also, as the article suggests, poker strategies are advancing quickly. I started in 2004, and by 2012 I was still ahead of the curve, but the game had clearly gone light-years forward in terms of general strategy--in particular I'm speaking to HUSNGs, my game of choice.