I have the NO-MAR changer bolted to my garage floor. It's great for front tires and softwall "sport" tires. I just tried to put on a new Pirelli Strada "E" tire with it and couldn't get it finished. Had to take the rim and rubber to a local shop. Now, the local shop had a Coates manual tire changer. It took 3 guys together (and these guys do this for a living!) to put that rubber on the rim.
Don't get me wrong, I like the No-Mar. Easy to get rubber off the rim, and front tires are a snap. And some rear tires will be easy. But I think most of us vertically challenged, out of shape couch potatoes are going to have trouble swapping on stiff side wall reinforced touring tires by ourselves with any of these manual gizmos. I have had success putting other rear tires on, just not this new Strada.
Now Smitty141 will tell you he can change tires with his all day long. I think he uses the special clamps that No-Mar sells to help hold the rim and rubber instead of a second (or third) person to help out. And he does it often enough that he has the knack for it.
I think the Harbor Frieght unit will do you well. I think the No-Mar is much better, but still not a panacea. YMMV.
I'd really like one of these:
Tire Changer
but alas, I found a shop to put the rubber on the rim and balance it for $15. That's a lot less than the tire changer. So I'll stick with the No-Mar. Maybe I'll eventually get the knack for those tougher rear tires.
Good luck with your changer!