The capabilites of an i7 outperform the capabilites of an i5. So your you look at performance yes it is better but if you look at bettery life the i5 will probably have better performance. the same goes with the i3 versus the i5 as the i5 will perform better and cost more.
http

/www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i5-4200H+%40+2.80GHz