I'm pretty aggressive about my training, but I've decided shutting the engine off for a practice landing is not for me. Here are my reasons:
1. I'm too chicken.
2. I've screwed up more than one simulated pattern on the short side. My engine starts immediately, but what if it didn't?
3. There are so many variables in every power off approach and landing that a minor difference in thrust/drag from a windmilling engine to a stopped engine might not make a big difference in training value.
4. Things would have to be "just right" for me to do this, and I don't train for things being just right.
5. I often try a no power approach/landing without a lot of planning. I'd do a lot less of them if they had to be successful.

Bill Kennedy
N42BK