M's monitor is able to monitor S3's and do some things automatic to them. I don't understand question on S+. Yes they can very in speed, but should be faster then B1/early regular S3's. (Not always true some were better then others but just a general rule also depends on clock speed you use)
What is m's? link?
Whats the best clock, or do I need to tweak each, any guides? it's crazy the difference on them,
I just ordered 6 SP20 to up my numbers
In my experience each needs done on their own on S3's. Yes they very greatly especially if early batch vs a good S3 plus.
M's - https://bitcointalksearch.org/topic/ms-miner-antsp-monitor-v52-alertsautomassscheduled-rebootmobile-miner-596178