Basically,master yi have jungling abilities so i choose it as a jungler to acheive maximum advantage.

I always asked for a help in killing blue so that i can get level 2 fast and effective jungle in wolves and wraiths and double golems then having meditate to heal and smite the lizards.After that kill the wolves again/find gank chances/return to get your markred.

Summing up the pros and cons.
Master yi>High dmg output>high speed>good at chasing and running to/from champions>able push turret fast>Good at counter attack>Good at solo champions>Alpha strike can catch up with enemies.
Master yi>When received stun in early games you are probably dead.>Master yi's alpha strike often ks other lanes in ganking>when champion that is locked by alpha strikes back away to turrets and allies master yi is 100%dead.So be sure that u use it at the correct timing