I’ve owned mine for about 35 years and use it every time I replace front springs. It was a reasonably expensive version of the internal type that looks like this:
It also made it easy to assemble my front suspension before it was installed in the truck:
I’ve seen cheaper versions start to unbend the arms under tension, or partially strip the center bolt. So rather than buying a cheap model it would probably be wiser to rent a commercial spring compressor if you choose to use one.
A compressor may not be essential on short springs, but most of my installations have been either full length stock springs or station wagon versions that are even stronger or taller. And even when using a spring compressor I always install a safety chain through the spring and lower control arm, with the ends of the chain connected together with a bolt. The few minutes it takes to use safety equipment just seems like cheap insurance compared to getting hit with a flying spring in the unlikely event something goes wrong.
I’ve never used a compressor on the rear springs of our trucks because they just aren’t needed. Spring tension is completely relaxed once the control arms are lowered.
I won’t replace the tool I already have because it will rarely if ever get used again, but if I were just starting out now the external type shown below might be easier to use. I don’t remember these being available when I bought mine:
