Reproduction: Advantages and Disadvantages?

In my Ecology class, the topic of sexual reproduction and asexual reproduction was introduced. Our professor discussed that advantages and disadvantages of each. One of the big advantages to sexual reproduction is genetic variation. Genetic variation allows for better adaptation which allows more offspring of a species to survive. The main advantage of asexual reproduction is the ability to produce more offspring.
The disadvantages were also discussed. The disadvantages of sexual reproduction are danger to the individuals involved and it requires more energy. The praying mantis is good example of the danger that is associated with sexual reproduction. In some mantis species the female will eat the male after they have mated. There is scientific evidence that there is a evolutionary benefit but one the scale of the individual it is detrimental.
Then there are species that are classified as having facultative sexual reproduction. Basically they are involved in sexual and asexual reproduction. Many example of this are in the plant kingdom. When conditions are good they are mainly asexual. Asexuality allows for more offspring in a shorter amount of time. When conditions are not ideal many of these plants reproduce sexually. This allows for more gene variation and a slower reproduction rate.