One worker means you can have one config across all machines - if you have a working config and machines are identical - you can literally copy your startup command to every machine you want to run from and go.
Disadvantages - if you're mining with a pool that provides you stats per worker - you won't be able to tell which of your machines is performing well, not so well etc. - as all of your stats will be reported as one worker vs. using multiple.
make sense but seeing his stats ,it's not really desirable as each machines only shows 2 to 10 khs rate and all the machines average are only 5khs ...but since he's got 30 machines on one of his cafe and 50 more from his other branch he will still run in profit but don't want the idea of getting his graphic cards to mine ..
