I have two. One is a Craftsman like you decribed, and I don't like it. A stock spring is ok, but if you try a stout spring, it twists on you.
The other one I have is a Snap-on, and it works very well.
There are also the type that sits on the spring and fingers grab the coils and compress. This works well when the engine is in the car, or head is on the engine. The downside to this is that you need small fingers to get the valve lock out, or put them back. A magnet helps for removal.
There are also 'cats paws' which are just crowbar like devices which pivot on the rocker arm stud. They work ok, but you need good biceps if you have stout springs, and you must be careful not to cock it and gall your valve stems or rocker arm studs.
My favorite is my Snap-on, and if the heads are on, the finger type compressor.
The cats paw is the quickest if the springs are stock.
SteveLaRiviere/Webmaster -- MCA # 47773