I've personally had great success with plyo's, doing them even for a month I noticed a significant difference in my vertical leap and power off the mark.

Recently I've been looking at plyo's a lot, due to my changing needs (no longer boxing, but for afl). They can be extremely benefitial, but only a few golden rules...

1) You must be fresh, you do them at the start of training and no more than 2-3 times a week, a day of rest in between. If you do them at the end of training, you run the risk of injury and gain not nearly as much benefit.

2) You must be decently conditioned already, there's not much point doing plyo's unless you already have a good base strength already. It can be a good idea to strengthen the legs first. Although a lot of boxers do a lot of burpees/squats/tuck jumps already, which should be adequate.

3) Don't overdo it, plyo's are comparable to sprint training. The efforts should be short, sharp and at max effort. People who are starting off are suggested to do about 60 "touches" max per session.

Why the change of mind scrap?