If you are a weekend warrior that won't be using that jigsaw, sledge-hammer, or socket-set on a daily basis, then this is the place for you!
The quality is better than you would expect, especially considering the drastic cost difference compared to the big name tools you see at Lowe's or Home Depot. They have a lifetime guarantee on tools - but at the cost who really cares?
The main tools that I use from here are my $5 socket set that I actually use on a regular basis. My orbital sander has seen a half-dozen uses. Blades and drill bits are cheap here - and for wear items that's what you want. my table-saw blade works just as well as the $15 counterpart.
What I like is that I can get odd-ball tools that I need for a single project now, and might or might-not need again (like fish tape or angle an grinder). I end up lending stuff to neighbors who thought you had to spend a bunch of money to get the right tool for the job. Now mind you, I still own a porter cable drill as I found the Harbor Freight ones a little cheap. But my dremmel, orbital and oscillating sander, and hammer drill are all harbor freight brand.
The other nice thing is the coupons - %20-25 of your purchase is fairly normal - and that $5 socket set got me an electric fly swatter with a coupon - and the pure joy I receive from eliminating those flying pests was so contagious that my neighbor got on as well.