oil for 2 stroke?

[2182]

i am wondering if it is worthwhile to run expensive oil in my 2 stroke johnson. i have been buying johnson/evinrude oil for $55/2.5 gallon now for a while. the boat i tournament fish on (read: gets motors beat hard) uses cheap pennzoil walmart oil. i used to use quiksilver but have been told its all marketing and is cheap junk. any insight? is two stroke oil all the same but w/ marketing and pricing differences? is there one oil that stands above the rest? should you only use your manufacturers oil? there are lots of people on here w/ vast motor knowledge, lets hear it.