We flare fine, but if we get too slow (a/s in the flare) on practice autos, we may not have enough power to arrest the rate of descent. Lots of weight and inertia falling out of the sky. Depends on the weight. Best weight to start practice autos is about 49-50k. Nr tends to build rapidly in the descent and flare, so lighter is better.
I prefer to be even lighter than that....say about 45k or less, and with a nice 10-15 kt headwind. You generally tend to float in the flare and it makes them much more comfortable.