octane boost is good, only use it if you have to... e.g. when your using 95 or when ur gonna race someone
i've used it before and yes i feel the extra boost not much but it works magic cheers hope that helps
also the come in different brand but the all work the same u wont notice the difference in brand unless u put it on a dyno and you wouldn't wanna waste ur time seeing which one is better they all do the job.