Hi there, I am using a Quick Jack and have lifted my 79 T/A with it.
I will start by saying that, in general, I love the QuickJack. It's super easy to use, amazingly stable (on most cars - more on that in a moment), and really compact if you have limited space (like us). I've been using it for couple years now on a variety of cars, but just started using it on the Trans Am. On cars like a Datsun, Mazda RX8, Miata, Lexus, etc they have provided great convenience for brake jobs, oil changes, exhaust work, etc. I've done a clutch and full transmission change with one as well. They lifts are heavy - the picutre shows some guy basically just throwing them around to move - yeah, not really the case. They do have wheels and can easily be moved around a garage though. Just not gonna "toss them in the trunk" and take them with you... The other thing is that you can use them length-wise (front to back) or sideways (one for the front, the other for the back) - they just have to be parallell or it can be dangerous. This is imporntant for a couple of reasons - depending on what you want to work on you can best position the quick-jack so that you can slide under the car from the side or from the engine / back. Last thing - it might be overkill, but I dont trust my life under any jackstand or quickjack without using a backup such as a wheel or two just incase the primary fails.
Regarding the Trans Am - I'm still working this out. Normally you use the QuickJack on the pinchwelds under the doors (front to back or side to side) but I'm not comfortable doing that on the TA yet as I'm not sure how they will hold up. I used the quick jack further toward the center of the TA putting one rubber pad under the front subframe and one on the rear. It lifted fine and I changed the gastank without issue of height, clearnace, or anything else. However, when I did the rock-test (push the car to check stablilty) it was a bit wobbly which would make me too nervous to crawl underneath. I'm now going to play around with using the quick jack side to side (one for the front of the car, one for the back) to see if stability improves. The issue is you would not be able to slide under the car front-to-back as the jacks will be in the way. As far as changing tires, doing brakes, oil changes, diff fluid, etc. it works great.
If you want to connect directly and do a facetime or just PM me and we can work it out. Happy to show you whatever I can. Good luck!!
Dan