Personally I love map, reduce, filter, find and I am using them from a long time. They helped me write clean, precise, fast and to the point code which align with my thought process. I use for loop when i have no choice left. As far as optimisation is concerned, map/reduce/filter/find replacement should be the the last option or not an option depending upon what level of optimisation is required.
Note: If you’re using loops, always use them idiomatically since compilers are now smart enough to correctly optimize idiomatic loops
I am happy to receive any feedback may be positive or negative.
Update: Here you can find the result for large data set and heavy computation.