I have implemented the Redis Object Cache on more than 50 sites so far. All of them are working well without any error. Had some serious performance issues on 2-3 websites though where I disabled Redis Object Cache Plugin and high resources problem was resolved.
I don't know how to correctly measure the difference in speed before and after implementing the Redis Object Cache. The frontend tests such as Pingdom, GtMetrix, Webpagetest etc doesn't show any measurable difference in the load time after implementing the Redis Object Cache.