This is a brilliant training aide. Any reasonable golfer will immediately feel the benefit of using this equipment but a complete beginner may struggle with it. Very quickly you get to feel what a good swing should feel like and you can learn to build up the all important lag. There's no doubt that it strengthens your core muscles in this process and it's worth taking with you down the range even if you do get a few funny looks. It's also great as a warm-up tool: a lot better than swinging a couple of clubs.
Contrary to what you may have read elsewhere, there is nothing wrong with the build quality. It's very robust and I can't see anything that might come apart! After using it for 2 weeks I added about 10 yards to each iron and 20 yards to my drives. Now I use it all the time because as well as helping the golf swing it works on the muscles in your waist.
I also bought an Orange Whip trainer for a friend so I was able to compare the two products. The SKLZ is a bit heavier so if you are a senior or junior you might be better getting the Orange Whip. However, I prefer the SKLZ because it is heavier, half the price and the grip can be changed; with the Orange Whip it's not so easy to re-grip.