Interesting angle from writer Pia Bergqvist in US Flying magazine May 2015 in his article Mastering No-Power Approaches.
Here are some extracts from his article: "While challenging, the ability to consistently complete a successful no-power approach is definitely achievable - glider pilots make one every time they fly - while you may never experience a true emergency, the day you do you will thank yourself for practicing dead-stick landings in various conditions - I would rather have a skill that I don't need than need a skill I don't have".
Another extract: "While you should target the best glide speed initially, it may not be optimal once you get closer to the ground. I would not ever use my best glide speed as the approach speed because you have no options if you are short. If I use 15 to 20 mph over my best glide speed in the circle to land, it keeps me closer to the runway because I am diving down and turning in a smaller radius than if I slowed to best glide and tried to do a circle to land based on that. With a strong wind you my not be able to make the runway
Also, seeing that you may end up short, you may be tempted to raise the nose. It makes you feel good for one second and then you start sinking faster. It is an evil start of a cycle that has resulted in many pilots landing short of the runway and even stalling the aircraft with devastating outcomes
With a few extra knots in the bank, you can trade speed for altitude if you get low. And if you need to bleed off speed or altitude, there are many options. You can add flaps, bring the prop forward, or slip and skid the aircraft".. End quote of extracts and certainly food for thought.