TechTool Pro is pretty good about detecting bad blocks on a drive. If it passed the long scan then I'd say there's nothing wrong with the drive itself.
What is the issue that makes you think there might be a problem?
Sometimes Mac is sluggish however it's only 5400 RPM running mavericks on a 6GB Ram late 2009 MacBook. Also I have to reset the SMC every 2-3 months due to the fan always running and never going below 6200 RPM.
Just being sluggish doesn't necessarily mean HDD failure. When you say sluggish do you mean constant beach balling?
When it first boots up it usually is a little slow, but after everything has loaded it seems to be fine.
When it first boots up it usually is a little slow, but after everything has loaded it seems to be fine.