Other than devices that add energy from a stored reserve, like hidden motors in bicycles, I have a really hard time drawing a line of "cheating". Why were shark suits banned? [1] Why is blood doping to allow for quicker recovery "bad", but a finely calculated nutrition regimen to allow for quicker recovery de rigueur? Why are these fancy new shoes so egregious, when compared to races run 50 years ago, the current shoes are futuristic and unobtainable.
Excepting the most basic sports (running), every other sport is reliant on technology. So there's no way around advancement.
And I'm in favor of it! I want to see more awesome suits that blast world records out of the literal water. I want to see someone top 2:00:00 in a marathon. I want crazy new F1 cars with ideas no one's had before. Let's do it. That's more "human achievement" than some guy running really fast.
[1] "Because Michael Phelps complained." http://www.thedailybeast.com/articles/2012/07/25/why-ban-ful...